stroke that 396-402 bbc with a 4" 454 crank or even 4.25"


Staff member
having done that a few times, read these links and comments
building a 400hp-500hp 396-402 big block can be done with carefully selected parts on a tight budget, but do your research and don,t jump into a project blindly.list what you have and check with a local machine shop, do some research, talk with your favorite cam manufacture and think about your options, and budget.
use of the externally balanced damper and flexplate or flywheel on a 4" or 4.25" stroker crank in a 396-402 will be far more cost effective than internal balance components on most applications!
any of the major piston manufacturers can fabricate pistons to match your needs, if they know the engine family, exact stroke, exact bore and connecting rod length, some keep a great many pistons in stock that they may or may not list, so youll have to call the tech dept and ask, don,t assume anything.

heres a source for the pistons to be used with a 454 crank, in a 402 / 396 BBC , the pistons and rods on the 454 crank must be re-balanced along with the flywheel and damper
occasionally minor block clearancing may be required
the stock 396/402 or 454 rods could be used but there are FAR stronger aftermarket connecting rods with ARP 7/16" bolts


they are designed to match

Compression Ratios





Ring Packs


Ring Sets

Pin Number

Lock Ring


.180" closed chamber hollow dome, centered pin. Made from Chevy 396 block, 454 crank. Will fit Edelbrock 110cc heads. Cast iron moly ring set 4125AM8. Piston and ring set kit KB361KTM.

obviously if you need a .030- or -.040 over bore size that should be ordered to match the application.

reading sub links helps a great deal

If you decide to go with the stroker assembly to add displacement and compression, you'll need to change both the crank and pistons, and in most cases , when building a stroker 396 or 402 into a larger displacement as the pin height or rod length needs to change as the stroke increases,the connecting rods should be upgraded to the better aftermarket or at least the 7/16" rod bolt O.E.M. rods if your intention is to run the crap out of the engine under performance conditions.
If your building a 434 to put in a pick-up to make towing your boat or race car easier that with the current 396bbc engine , be conservative on the cam duration, Id suggest some thing like a crane #103052 flat tappet hydraulic
Ive build at least a dozen 396-402 big blocks and if your, dealing with one of the lower compression engines and are going to keep the same low compression your definitely restricting the engines potential, one rather common upgrade is swapping to a different set of pistons and a common 454 crank, and a cam with a tight lsa and a bit more duration plus reworking your current heads for more flow , the links below will help.a good detailed set of stock oval port heads and a roller cam might get you to your goal if you had more compression, but going the 4" crank stroke from a 454 crank which won,t cost much,compared to some other routes you might consider with different pistons makes it far easier.
but before you start, price out the parts and machine work, youll occasionally find really good deals on used 454 engines making dealing with your current 396-402 a waste of money, because if you can get a significantly larger displacement engine built to similar compression, it will produce better torque in most cases. and its almost always at a lower cost,to build a larger displacement big block if you start with the more common 454 block.
yes theres occasionally minor block clearance work, to fit the 454 stroke crank,in a 396 block, but most times not, that depends mostly on the connecting rods used and yes the assembly needs to be rebalanced,Ive generally used the 454 flexplate and balancer, getting 500hp out of a stroked 396/434 is hardly difficult if your willing to put some time and effort into researching the parts required and careful assembly
you could easily spend $1200-$1900, OR MORE! on a complete rotating assembly, balancing and machine work required to build a 396-402 stroker that had 434-454 cubic inches built from a smaller bore block, and most local machine shops can sell you a rebuilt 454 for less, add up all the parts,machine work , make a detailed list before you start ask lots of questions, you might find theres other lower cost options
before you even consider having a 396 BBC block bored to 4.25" bore diam. (or any more than a .060 over bore ) for use in a serious performance application and adding a stroker crank, etc. ID strongly advise having the block walls sonic tested to be CERTAIN youll still have a MIMIMUM OF .180 bore wall thickness AFTER its honed to size,and magnaflux checked for cracks,RIGID CYLINDER WALLS AND GOOD RING SEAL & HIGH COMPRESSION,WILL PROVIDE BETTER POWER THAN THE MINIMAL GAIN FROM A SLIGHTLY LARGER DISPLACEMENT BORING A 396 BLOCK, and GOOD USED 454 blocks cost less than all the machine work in most cases

read this link
yeah you can ignore that advise but it frequently gets expensive if you do, in most cases
chevblockparts003.jpg ... &Itemid=25
Here is a handy formula for finding the engine size of a V8 engine:

engine size = bore x bore x stroke x 6.2838



All dimensions should be in inches.

Ive built a few 396/402 engines with the 454 crank and custom pistons over the years and while its not a 427/454 ,
it generally allows the owner to provide the car with a reasonably lower cost combo that provides surprisingly impressive performance,
if you can find an rework something like a set of 781 oval port heads and a decent intake,
yes you need to do the math and select the correct compression ratio,
a low restriction exhaust and headers and select a cam that allows the engine to breath well.
no you can't randomly slap parts and mis-match drive train gearing and expect it to work.
but get the combo up to about 10:1-11:1 and get a rather tight 106 -108 LSA and about .600 lift,
about a 245 duration, a 800-850 cfm carb, and a 4 speed trans and a 3.73:1 rear gear in a camaro or nova and its a fun ride


related info


viewtopic.php?f=69&t=2900&p=18448&hilit=peanut+port#p18448 ... defc383645 ... &q&f=false

remember a standard big block chevy has a block deck height of approximately 9.8" , stock rods are 6.135" long center to center

your cars rear gear ratio, your stall speed if its an auto transmission, and your heads and intake will be critical to success, because of the long stroke in relation to bore diam. and your trying to run on the street with some retained drive ability, you've got a wide range of cams that will work, in a similar combo I suggest a flat tappet solid lifter cam, or roller cam, with about a 245-255 duration a tight 104- 108 lsa and as much lift as you can get, if your trying to maximize the hp potential, a milder cam on a wider LSA lets say a 235-245 duration on a wider 112-114 lsa will cost some hp but make it much more drivable on the street, naturally you'll want to have a long detailed discussion with several cam manufacturers BEFORE selecting a cam.
be aware that youll need to know your rear gear ratio, transmission, and what compression ratio your dealing with before you call your favorite cam manufacturer.
if your limited to pump octane gas its best to keep the dynamic compression in the 8.1-8.2.1 range, and the duration reasonable for the cars weight and gearing
oval port heads will generally be correct for this displacement range and theres several good choices, in G.M. EDELBROCK,BRODIX,TRICKFLOW and AFR

be careful and do the research , because if the compressions to low or if the cams, got to much duration, for the application, or youll lack low rpm torque , , get too little duration or the compression to high and detonation becomes an issue which will make it less than ideal for street use, in either case, but , a carefully thought thru combo can still be functional if matched to the correct stall and rear gear ratio, in your weekend warrior muscle car. naturally that will require a compression ratio of at least 10:1-10.5:1 , with the longer duration cams and a bit less with a milder cam. and for street use oval port heads and a dual plane intake will usually be about right like an EDELBROCK PERFORMER RPM , or similar intake ... r-kit.aspx ... index.html ... _rods.html ... -138464216 ... ewall.html

pistons ... defc383645

lifters crower 66900Px980-16

nice street mild performance cam
crower cam

on a #00057 premium core
6834 springs
87063 retainer

a 2800-3200rpm MINIMUM stall converter or a manual transmission,and a 3.73:1-4.11:1 rear gear ratio, and at least a 7 qt baffled oil pan

decent choice in a mostly race combo
crower #01298 ... 8&x=16&y=4

or ... il&p=24440

this ERSONS well known for working well with a manual trans and at least 10.5:1 compression , and a 3000rpm stall converter and 3.73:1 rear gears , used in several engines ... rers_id=27

obviously you must match the crank throw distance, rod length and piston pin height, bore diameter, ring size and bearings matched as an assembly to the application and get the assembly balanced

Ive always been confused,and amazed by the guys that will build a 383-406 SBC and rave about the results but who stick their nose up at building a 396-434 BBC engine that has FAR greater potential with its better heads, larger valves , and stronger components, getting 500 plus horsepower from a properly built BBC is an easier task than from a similar displacement SBC, in most cases, and while the sbc might be cheaper to build the price difference might be a great deal less with a 396-434 than you might think
the 402 BBC is one of the most UNDER RATED engine out there, ID far rather build an engine based on a 402 BBC than on a 400 sbc.

Ive NEVER been able to figure out why so many guys swoon and get chills over a 383-396 SBC built from a 350 combo and IGNORE a 396-402 BBC combo with its larger ports, bigger valves,stronger parts , far better valve train and much larger potential in displacement, and head flow rates , especially if you go the stroker route, and basically better architecture, that allows a 434 displacement with readily available parts, yes theres the extra 80-100 lbs of engine weight and the packaging space issues, but in most cases the BBC can make enough extra hp to at lease equal and in most cases easily surpass the similar SBC combo,it just takes some research and thought going into the selection of the components, given the choice, between a sbc and a BBC and if not restricted in my component selection,Ill build a BBC every damn time! (especially if I can build it to maximize the BBCs true potential)
yeah, theres no question you can build a killer sbc 383-396 slightly cheaper as the basic components are more common and cost slightly less, but the difference in total cost is generally far less than most guys realize once you try to exceed about 475-500 TRUE hp.
Even a standard bore and stroke 396 or 402 displacement big block should EASILY be able to produce power levels equaling or surpassing the similar displacement in a small block engines architecture

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Staff member

Assembly lube ACXAC-9900 Ackerly & Childs $8.99
Piston rings 1/16 Ackerly & Childs 138.00
Cam bearings FH615F Competition Products 29.99
Core plugs P102 Competition Products 7.99
Distributor driveshaft 8151 Competition Products 11.99
Fuel pump drive CCA4616 Competition Products 13.99
Funky parts kit FKC-3 Competition Products 7.95
Gasket set RB-31170 Competition Products 39.99
Long steel rockers N/A Competition Products 80.00
Oil pump N77 Competition Products 36.99
Hydraulic roller 396275/284 Isky 335.95
Hydraulic lifters 3970HYRT Isky 645.95
Timing chain set 73142 Manley 94.50
Distributor D100700 PerTronix 275.09
Wires 808290 PerTronix 60.87
Bearings 829KDSS Pro Comp 69.95
4.155 piston N/A Ross 917.00
4.250-inch crankshaft QT425 RPM 260.00
I-beam rod CBC6385-I RPM 525.00
Champion spark plugs NY8 Westside Performance 31.60
Intake valves 11872-8 Manley 150.48
Exhaust valves 11381-8 Manley 150.40
7-degree valve locks 13084-16 Manley 51.20
Springs 22408-16 Manley 161.60
Retainers 23645-16 Manley 52.00
Spring cups 42126-16 Manley 67.20

If your intention was to maximize lower rpm torque in a 396-454 with peanut port heads , for use in towing a heavy load, at lower speeds,
they are certainly designed to do that, I.d say peanut port heads and a mild cam (similar too but certainly not limited to this one, obviously check clearances, and dynamic compression )

and ideally about 9:1 compression would be about ideal for your intended application.
long tube 1.5"-1.75" headers similar to these, and a low restriction exhaust would help.}&gclid=CICK9qnA-dUCFQ2DMgodaWwCcQ&gclsrc=d

wieand makes a specific intake to maximize peanut port head flow, in the lower and mid rpm ranges

346236 1975-87 454 Open 113cc . combustion chamber PEANUT port

dynamic compression should ideally be in the 8:1-8.1:1 range

try to get the quench distance in the .040-.044 range
with the 113 combustion chamber a 15 cc-17 cc dome gets you near 9:1
hyper-eutectic pistons would be fine here.
I would try to find a 4.20-4.3 diameter head gasket

obviously ask the manufacturers tech dept, if they have any suggestions and if they have had and clearance issues using your part number cylinder heads with the pistons your about too order, just to reduce any potential problems, yes youll want to manually verify piston to valve and piston to combustion chamber clearances

related info


Pit Stop: Edelbrock 100cc Big-Block Oval-Port Heads—A True Bolt-on?
Written by Marlan Davis on December 15, 2016
Edelbrock - Photographer;

Which Edelbrock Head Yields 9.5:1 Compression on a Stock 1971 402?

I have a 1971 Chevelle SS that I bought new. It is a 402 big-block, four-speed car with 3.31:1 gears and is stock. I want to freshen the engine up by increasing the compression ratio from 8.5:1 to about 9.5:1 (I still want to run pump gas). I am thinking of a Comp Cams 280HR Magnum hydraulic-roller cam and kit, an Edelbrock Performer RPM oval-port manifold, and Edelbrock Performer RPM oval-port heads—either PN 60435 or 60455. My stock heads are open chamber with 113cc chambers. The 60435 head has 100cc chambers, with 60455 having 110cc chambers.

Which head can I use to achieve about a 9.5:1 compression ratio? I have gotten all kinds of opinions on this; they are all over the board and I am totally confused. My stock piston has casting No. 3995849 and the Sealed Power stock replacement is PN 402P. I am told that the Edelbrock heads won’t work because the piston will hit the spark plug because the plug has been relocated.

—Larry Musto


For Larry Musto to truly get to 9.5:1 with modern Fel-Pro gaskets on his existing short-block, even Edelbrock’s 100cc heads require milling—but by now it’s time to refresh that tired original motor. With the right head gasket and block deck height, 9.5:1 is easily obtainable with stock (but better quality) Speed-Pro forged replacement pistons.
Likely, neither head will do it out of the box. Your 1971 402 will only achieve its rated 8.5:1 compression ratio if the block, the rotating assembly, and the cylinder-head combustion chambers were blueprinted to the exact minimum design dimensions—and that’s with the original thin, steel-shim, 0.021-inch, compressed-thickness head gaskets! In the real world, an original, nonrebuilt, stock, unblueprinted engine could easily be at least a half-ratio lower than “it’s supposed to be” because, for example, the blocks are not machined to minimum to allow for “worst-case” tolerance stack on the non-blueprinted internal components.

That said, whatever your true compression ratio is now, the 110cc 60455 won’t come close to meeting your target on the existing short-block. The 100cc Edelbrock 60435 has the potential to raise the compression ratio just shy of a full point compared to your existing 113cc factory head—assuming no other changes, including the use of that OE-type, thin head gasket. But with aluminum heads, you’ll need to use a “thick” composition-type head gasket to reliably seal them on the block. (In fact, I frown on shim-type head gaskets even with iron heads with in-service engines unless the block and head decks are dead-nuts flat.) A “thick” gasket will lower the static compression ratio about 0.3 point on your 402 compared to a thin shim gasket.

By a “thick” gasket, we mean a modern-performance, aftermarket, composition-style head gasket (such as Fel-Pro PN 1027 or 1037). These 0.039-inch-compressed-thickness head gaskets have a reasonably small 4.370-inch bore, so they yield the smallest compressed volume (9.7 cc) of any of the gaskets in Fel-Pro’s composition-type big-block Chevy performance head-gasket line. Which of the two gaskets should be used on your engine is based on the block deck’s cooling hole locations; 1971 was a transition year, so compare the gasket photos on these pages to the deck holes in your block.

But will the 60435 100cc head hit the pistons? Edelbrock says the 60435 head develops “9.2:1 compression with flat-top pistons,” but that’s on a 454. Your small-bore 402 piston still has a slight dome, so we now need to address the question of chamber configuration and spark-plug location.

According to Edelbrock, only its E-CNC oval-port big-block Chevy heads, as well as all of its rectangular-port big-block Chevy heads, have revised spark-plug locations that may require pistons designed around the specific cylinder head. Edelbrock’s Performer and Performer RPM oval-port big-block heads (including the part numbers you’re considering) are said to maintain the standard spark-plug location. But in the case of the 100cc 60435 head, there’s a catch: To reduce chamber volume from the normal 110cc Edelbrock chamber to 100 cc, Edelbrock rolls over (angle-mills) the head decks 1½ degrees from standard. This design improves intake-port alignment and provides a smaller combustion chamber without shrouding the valves, but yes, it does effectively relocate the spark plug slightly.


This is a standard 110cc combustion chamber in Edelbrock’s big-block Chevy oval-port head, PN 60455.

This is the combustion chamber in Edelbrock’s 100cc “rolled-over” 60435 oval-port big-block Chevy head. Compared to the 110cc chamber in the previous photo, this head has a slightly rotated chamber to unshroud the valves. Also note how the 100cc head’s far-side wall is pulled in slightly.
The old-school rule concerning domed piston head compatibility on big-block Chevys is: Closed-chamber pistons usually are OK with open-chamber heads, but open-chamber pistons shouldn’t be used with closed-chamber heads. But, again, we’re in a gray area: Your stock iron 1971 113cc factory chambers are neither fully open nor fully closed. The Edelbrock chambers are considered to be semiopen; normally, closed-chamber domed pistons work fine with the larger-chamber versions.

In the case of the rolled-over 100cc head, the best information I have is your existing 1971 factory piston or aftermarket equivalent should be OK, but—because the head is angle-milled—don’t exceed a 0.150-inch dome height on a zero-decked block (piston deck is flush with the block deck at TDC). If the piston deck (the flat part of its top surface) is below the block deck at TDC, the amount the piston is below the deck can be added to the allowable dome-height value. If the heads are milled to reduce chamber size from the as-delivered 100 cc, subtract the amount milled from the allowable dome-height value. Nevertheless, prudence dictates claying the piston to check for interference, then grinding or machining the piston for clearance as needed. Of course, piston-to-valve clearance should be checked with any big aftermarket cam. Remember, Edelbrock heads also have bigger valves than the ones installed in your OE heads. These rough rules assume use of a typical “thick” head gasket.

How, then, can you reach 9.5:1? The easiest way is to mill the 100cc Edelbrock 60435 heads. Edelbrock says up to a 0.060-inch cut is safe; every 0.005-inch reduces the 60435’s chamber volume about 1 cc. Again speaking hypothetically, let’s say your existing pistons are 0.018 inch below the deck at TDC, typical for an uncut production block. Sources differ on the dome volume of the stock pistons (and so-called stock replacement pistons are not always exact duplicates of the OE piston), but NHRA specs claim the stock cast piston’s dome volume is 12.10 cc. To get to 9.53:1 with these specs calls for a 95cc chamber—therefore, the heads require a 0.025-inch cut to reduce chamber volume by 5 cc’s [(100 cc – 95 cc) × (0.005 in/cc) = 0.025 inch]. The OE piston supposedly has a 0.112-inch dome height, which should provide sufficient clearance: 0.150 dome height allowance + 0.018 deck height – 0.112 piston dome height – 0.025 head mill = 0.031 allowance remaining.

All this is by doing the math. But the only way to know for sure what your compression ratio really is would be to remove the heads and cc both a cylinder with piston as well as the cylinder head combustion chamber. You must cc and measure everything on your assembly, then figure out how much to mill the new heads to reach your goal.

I do hope by “freshen up” you mean that you are rebuilding the bottom-end, because that high-mileage rotating assembly won’t last very long with 150 or so more horsepower. That opens up many more ways to get to your 9.5:1 target. For example, you could blueprint the bottom-end, boring the cylinders 0.030-over. The relatively affordable forged Speed-Pro piston (PN L2383F30) is NHRA-accepted for your model year as a stock-replacement part and is stronger than a cast stocker, while its 13.90cc dome volume is close to OE specs. Square and deck the block to put the piston 0.010-inch below the block deck at TDC. This piston has a “should-be-safe” 0.110-inch dome height (0.050 remaining tolerance with a 0.010 deck and no head milling). Depending on crank stroke and rod-length variations, a 0.010 deck may require machining the block 0.005-inch below the block’s theoretical 9.800-inch blueprint deck dimension (crank centerline to top of block deck), but that’s OK; as I’ve said, your block is almost certainly taller than blueprint, so it will need decking).

Just tell your machinist what you’re trying to achieve. With the 100cc Edelbrock head and either of the listed Fel-Pro head gaskets this puts your now 408ci engine’s compression in at 9.52:1. Of course, with that big roller cam and modern aluminum heads you could run up to 10.5:1 on pump premium gas on a near-zero-decked block—but that’s a whole ’nother discussion.


Speed-Pro/Federal-Mogul piston L2383F30 is a close analogue to the stock cast piston but as a forging it’s more durable. A set of eight goes for $508.99 at Summit Racing. Using Edelbrock 100cc heads, compression will go up nearly a full point, assuming no other changes.

These Fel-Pro head gaskets illustrate the different coolant circulation patterns in early versus later big-block Chevrolet engines. See text for details.
These Fel-Pro head gaskets illustrate proper Mark IV big-block Chevy head gasket selection. For improved cooling, most (but not all) 1971–1990 Mark IV Chevrolet big-blocks use parallel-flow coolant circulation. They have three cooling holes on the block-deck’s exhaust side (A through C), and small single coolant holes at the rear of each deck (D and E). Any big-block Chevy head gasket with the appropriate bore size and thickness can be used—although a gasket with only the small water passages at each end (top, Fel-Pro Performance 1037 or Fel-Pro marine PN 17046) is recommended (only the gasket’s rear hole is “active” on each side). Prior to 1971, most (but not all) Mark IV Chevrolet big-blocks had series-flow cooling. At most, the block decks have only one lower coolant hole (C on the passenger side; A on the driver side), and there are double coolant passages at the rear of each deck (D through G; only the rear holes are “active”). Series-flow blocks must use Fel-Pro PNs 1017-1, 1017-2, 1027 (shown, bottom), 1057, or 1093. Although all big-block Chevy Mark IV heads and the performance gaskets shown here have the extra lower holes, they are nonfunctional without the extra holes in the block. Parallel-flow blocks can be converted to series flow by adding the missing holes using the appropriate gasket as a template.
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Staff member
Re: stroke that 396-402 bbc with a 4" 454 crank ... il&p=24670


that may not look super impressive but in a reasonably light weight car it should provide you with very brisk performance.


play with calculators

AFR just came out with heads that are about ideal for a hot 433 cid bbc (stroked 396/402)
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Staff member
Re: stroke that 396-402 bbc with a 4" 454 crank or even 4.25 use of the externally balanced damper and flexplate or flywheel on a 4" or 4.25" stroker crank in a 396-402 will be far more cost effective than internal balance components on most applications!

I have a set of BBC 291 heads that I want to use but they have been decked a few times so there is not much meat left on the bottoms. I don't want to take off another .010 unless I have to. What is the best way to check the decks to see if they are flat and avoid milling?


your probably going to be ahead in the long run to have a GOOD trusted local machine shop inspect the heads and check them for wear and cracks even if it costs you $100 to get that done!
and have them give you a detailed list of what needs replacing or machining and a brief description of WHY the work should be done.

at that point you can decide if you want to proceed with those components or cut your losses and upgrade without having a great deal into the parts. a good set of oval port heads (NOT PEANUT PORT HEADS) can be cleaned up and pocket ported to produce respectable power, but most of the designs are at least 30 years old so its hardly surprising that theres far superior aftermarket heads.
PEANUT PORT heads with smaller ports are not to be ignored on the 396-427 displacement big blocks, even those heads once cleaned up can support 500 plus hp if matched to the correct components and compression and cam timing etc.

you might also want to read thru this link[/color]

compare a few heads ... ewall.html

having worked rather extensively with big block chevy engines for the last 40 plus years I can assure you the stock configuration on most 366-427-454 car engines with only a few exceptions were restricted in power from what could rather easily be reached if your willing to do the required changes
adding an extra 100 hp or more with the addition of long tube headers, upgraded , low restriction 3" dual exhaust, a new more aggressive cam , intake and some head port work is very easily done

adding the correctly selected intake heads and cam, to a 396 with headers and a low restriction exhaust converts it to a totally different power level, and if you want to is also very simple to swap in a 4" or even a 4.25" stroker crank

viewtopic.php?f=69&t=2165 ... 1/A-P1.htm ... ewall.html ... ck_engine/ ... ewall.html ... ewall.html ... ewall.html ... 7/A-P1.htm
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The Grumpy Grease Monkey mechanical engineer.
Staff member
I was recently asked to provide info on building a lower cost 383 SBC-or 396 BBC
if given a choice ID say its a no brainier, the 396-402 BBC engines has a FAR STRONGER crank,
rods and BLOCK, larger valves and the worst flowing BBC heads,
out flow the VORTEC SBC easily with minor port & bowl area clean-up, find a set of one of several factory BBC heads
and you can significantly improve the flow potential.
lots of guys build impressive SBC, 383-406 engines but a properly built 396-BBC has a stronger bottom end,
and potentially better heads than most common SBC heads.
the only reason the 396-402 BBC is not a coveted prize , is the 427-454-496 BBC combos are potentially even more powerful
but a good well thought out 396-402 BBC has a good power potential thats commonly ignored,
exceeding 500 hp with a properly designed 396 BBC is not that difficult to do on a budget,
especially if you have a manual transmission,and a 3.73:1-4.11:1 rear gear
that allows you to run a bit more cam duration.
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The Grumpy Grease Monkey mechanical engineer.
Staff member
lets go old school, and reasonably low dollar

ID suggest a manual transmission and a 10.5:1 compression 396 short block,
a solid lifter flat tappet cam, like this one linked, below
(no it won,t work with stock valve springs and clearances)
and yes long tube headers are mandatory.
Id suggest the wieand single plane oval port intake,and a 750 -800 cfm carb
certainly mildly reworked 049 heads would work,
with the proper clearances and new springs,and a bit of port clean-up, work
but theres a decent chance , if you shop carefully,
that you could locate a set of used aluminum oval port bbc heads in good condition.
youll need long tube headers and a low restriction exhaust, but a camaro, nova, corvette or even a chevelle
with the proper manual transmission and rear gear would respond favorably.
you would certainly not be the first or last guy to build a 396-402 with a similar intake ,
that crane solid lifter cam and decent heads that might decide to add a wet nitrous system,
and easily run rather amazing times.
keep in mind anything you might do to a 396-402 would also work rather well in the larger bore and displacement BBC engines,
ask around at local machine shops 396-402 short blocks are rather commonly available at a significantly lower cost than the 427-454 block versions.
so thats the only major reason the smaller displacement versions get over looked,
thats really a mistake in my opinion as the marginally smaller bore BBC engines,
tend too have better head gasket sealing potential,
and respond very well to a radical cam, proper gearing ,
high compression and a dose of giggle gas!


wet nitrous

related threads
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The Grumpy Grease Monkey mechanical engineer.
Staff member
back in about 2007-2009
one of the local guys asked me a bunch of questions about stroking a 396 bbc / his 402 has a 4.125 inch bore
I suggested he find a standard 4.25" bore 454 block,
General Specifications. Chevy 402's displacement measures 402 cubic inches,
or 6.6 liters.
The BBC engine has a stock bore of 4.125 inches and a stock stroke of 3.76 inches.

but he decided to work with the existing 4 bolt 396 block he already owned/
he had a limited budget and I thought he had just given-up ,
well I heard from him recently and he had basically followed my advice
, on the build specs, and built a 4.25" stroke crank,
and about a 10:1 compression ratio,and the cam ,heads and intake matched to a low restriction exhaust and headers,
and remember with the smaller bore size and longer stroke, and high lift cam,
connecting rod to cam, connecting rods to bore wall lower edge, and block oil pan wall will require clearance work,
and you need to be careful doing that,
the piston to valve and bore wall to valve clearance must be carefully checked
and not need to rev the engine much to do so)
and a 402 BBC slightly over bore size block and piston combo.
to my surprise, he even used the

hydraulic roller cam

intake manifold

he has custom 4.185" diam.
pistons with a 1.27 pin height
6.385 rods


Im looking forward to see how it works out ,
as hes sticking it in a 1967 firebird
he has a 3.36:1 rear gear and a posi 10 bolt rear and a muncie 4 speed manual trans,
I strongly suggested not using slicks as that stroked 467 BBC,
should easily exceed 500 plus ft lbs of torque, over much of the intended power band.


common BB CHEVY piston compression heights are
remember the blocks deck height, minus the piston pin height minus 1/2 the crank stroke will equal the required connecting rod length
the blocks deck height, minus the connecting rod length, minus 1/2 the crank stroke. will equal the required piston pin height

some related BBC builds

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