Another 427 Tall Deck Truck/Marine

I am building this engine and I know you have a lot of links and post but (no offense) its like an unorganized library. I dont know where to look. So here goes: I am planning on using stock block 473478, stock tall deck intake 364462, Holley 850 cfm doublepump manual choke carb 4150, stock 336781 cylinder heads. I do plan on doing road course with her even though she's getting bolted to a turbo 400 with shift kit & 3:42 limited slip 12 bolt rear. I want to use L88 pistons. I cannot find them on Summit or jegs. I don't know if those pistons will hit the head. I want to be able to use stock heads for now. I need to use what parts I got since I'm running out of garage space. I plan on using Lunati cam 525/550 lift 280/288 dur. 112 lobe sep. Thank you for your time in advance.
 
L88 pistons require matching combustion chambers, and were designed to be run in a 12.5:1 compression ratio 427
with a 3.76" stroke and 6.135" rods and a cam with a good deal more rpm potential.
you would need to verify combustion chamber shape and clearance too run a L88 piston, and I doubt youll want 12.5:1 compression on the street.
336781.....73-85...oval...OPEN...454, 118cc chamber, 256/114cc ports

https://www.corvetteactioncenter.com/specs/l88/l88engine.html

you can not run L88 pistons on a stock 3.76" stroke crank and use stock length connecting rods,
in a tall deck block without making mods to the combo components used.

https://www.uempistons.com/index.ph...e=deck&zenid=823ce2c9e2ffa691864d832c10107df0

https://www.uempistons.com/index.php?main_page=calculators&zenid=823ce2c9e2ffa691864d832c10107df0
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1.765 compression height, pistons in standard 9.8" deck block, a 10.2" tall deck requires a longer connecting rod
most likely a 6.535" aftermarket connecting rod

threads you should read through carefully,and the sub links in them are below,
the tall deck block is put to much better use building a 496 with a 4.25" stroke and a .060 over bore and 6.385" connecting rods

http://garage.grumpysperformance.com/index.php?threads/another-496bbc.5123/

http://garage.grumpysperformance.co...g-block-head-comparison.319/page-2#post-61658

http://www.maliburacing.com/patrick_budd_article.htm

http://garage.grumpysperformance.com/index.php?threads/427-tall-deck-bbc.14451/

http://garage.grumpysperformance.com/index.php?threads/big-block-chevy-info.710/#post-60299

http://garage.grumpysperformance.co...-displacement-street-engine.10961/#post-50668

related threads
http://garage.grumpysperformance.com/index.php?threads/900hp-bbc-n-a-build.12227/

http://garage.grumpysperformance.co...le-of-what-a-pump-gas-bbc-combo-can-do.12330/

http://garage.grumpysperformance.com/index.php?threads/another-496bbc.5123/

http://garage.grumpysperformance.com/index.php?threads/helicoils-555bbc-build.1474/

http://garage.grumpysperformance.co...budget-iron-head-build-iron-headed-rat.14283/

http://garage.grumpysperformance.com/index.php?threads/468-build.11794/

http://garage.grumpysperformance.com/index.php?threads/565-cubic-inch-bbc-build.11824/

http://www.superchevy.com/how-to/project-cars/sucp-1208-big-block-heads-shootout-the-o-vs-r/

http://garage.grumpysperformance.co...-about-your-potential-dream-bbc-combos.14607/

http://garage.grumpysperformance.com/index.php?threads/oval-port-afr-head-565-bbc.11076/
http://garage.grumpysperformance.co...u-thinking-about-your-potential-combos.14607/
 
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Lots of guys prefer a 427 because it will Rev high.
Use a 427 or 454 standard block.

Been told by several drag racers that a 427 Tall Deck makes all off the shelf headers impossible to use.
 
L88 pistons require matching combustion chambers, and were designed to be run in a 12.5:1 compression ratio 427
with a 3.76" stroke and 6.135" rods and a cam with a good deal more rpm potential.
you would need to verify combustion chamber shape and clearance too run a L88 piston, and I doubt youll want 12.5:1 compression on the street.
336781.....73-85...oval...OPEN...454, 118cc chamber, 256/114cc ports

https://www.corvetteactioncenter.com/specs/l88/l88engine.html

you can not run L88 pistons on a stock 3.76" stroke crank and use stock length connecting rods,
in a tall deck block without making mods to the combo components used.

https://www.uempistons.com/index.ph...e=deck&zenid=823ce2c9e2ffa691864d832c10107df0

https://www.uempistons.com/index.php?main_page=calculators&zenid=823ce2c9e2ffa691864d832c10107df0


1.765 compression height, pistons in standard 9.8" deck block, a 10.2" tall deck requires a longer connecting rod
most likely a 6.535" aftermarket connecting rod

threads you should read through carefully,and the sub links in them are below,
the tall deck block is put to much better use building a 496 with a 4.25" stroke and a .060 over bore and 6.385" connecting rods,
the displacement increase, from 427 vs 496 is generally worth an additional 80-100 hp

http://garage.grumpysperformance.com/index.php?threads/another-496bbc.5123/

http://garage.grumpysperformance.co...g-block-head-comparison.319/page-2#post-61658

http://www.maliburacing.com/patrick_budd_article.htm

http://garage.grumpysperformance.com/index.php?threads/427-tall-deck-bbc.14451/

http://garage.grumpysperformance.com/index.php?threads/big-block-chevy-info.710/#post-60299

http://garage.grumpysperformance.com/index.php?threads/rocker-push-rod-wear-issues.9815/#post-54088

http://garage.grumpysperformance.com/index.php?threads/build-a-496-stroker-bbc.101/#post-49427

http://garage.grumpysperformance.co...-displacement-street-engine.10961/#post-50668
I don't have the kind of money to bore. I'm sticking with stock size also to help keep it simple.
 
Your going to need custom pistons made with a one off Pin setting to have 427 Cubes and a Tall Deck engine.
Stroker kits are made to turn a Tall deck 427 into a 496.
540 cubes is the max.

It will be a Fuel thirsty beast.
Need a True Drag Race fuel system to feed it optimized for Road Race.
 
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What some guys have done is remove the 3 rd compression ring off of the factory forged Tall Deck 427 pistons.
Ran it .
No rebalance.
 
while thats true it effectively reduces the effective mass a gram or two, I can,t imagine it has any effect that you could see,
the best solution from a performance perspective is to do the required calculations to select the longest length connecting rod and the lowest weight piston,
of a decent design that will reduce the reciprocating mass significantly more.
the tall deck has a 10.2" deck height, a good dual plane aluminum high rise intake manifold will tend to provide the best compromise if you use a low compression and mild cam duration,
while it might seem like a waste of time, now, reading the links and sub-links will provide a good base to work from, later and save you a great deal of wasted time and money

you have a choice, you can slap the components you own together, now and live with what you have built regardless of the results , or you can put some real thought into making the result perform and carefully select parts and significantly boost power... yes that routes more expensive up front, but in the long term it tends to get better results and cost LESS.
common BB CHEVY piston compression heights are
1.270"
1.395"
1.520"
1.645"
1.765"

remember the blocks deck height, minus the piston pin height minus 1/2 the crank stroke will equal the required connecting rod length
OR
the blocks deck height, minus the connecting rod length, minus 1/2 the crank stroke. will equal the required piston pin height

if you wonder why I suggest using SCAT (H) beam style cap screw connecting rods vs stock or most (I) beam designs this picture should show the increased cam to connecting rod clearance

After market performance ,big block connecting rods come in several common lengths
0704ch_15_z+chevy_big_blocka.jpg

0704ch_14_z+chevy_big_block+.jpg

notice the pin height in the pistons pictured above allow a longer or shorter connecting rod length


hrdp_0704_59_z+piston_tdc_diagram+.jpg

heres a selection of commonly available big block chevy connecting rod lengths

bbcdht.png

https://www.uempistons.com/index.ph...e=deck&zenid=823ce2c9e2ffa691864d832c10107df0

https://www.uempistons.com/index.php?main_page=calculators&zenid=823ce2c9e2ffa691864d832c10107df0
 
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He already stated Grumpy he has no money to Rebore oversize.
Also means no money for long length connecting rods.

A bit of a waste long rods in 427.
Might as well go 496 or 540 stroker kit.
That way you can use modern 400-450 cfm @ 28 inches water depression.
Make serious power.
Just need $8-10k to make it happen.
 
Actually a better deal than big inch stroker Pontiacs.
Those are $40 k typical.
Not real fast when done.

Pontiac 455 & 480 combo ends up fastest still.

540 BBC will deliver 900-950 hp no power adder.
 
almost all of us are operating on a strictly limited budget, yes I'm aware,moneys tight,
but if you simply re-ring and re-bearing a low compression truck, 427 bbc,
slap those stock non-reworked 781 heads on the rebuilt short block
and swap in a mild performance cam, you'll have a myriad of problems you may not be aware of,
first the valve train geometry and clearances and valve spring load rates and rocker geometry,
and piston to valve clearance , is very unlikely to be correct.
next the heads if not reworked are not going to flow nearly as much air/fuel as they potentially might,
and the truck tall deck engines rotating assembly was designed for operation in the 1000 rpm-4000 rpm range.
the original pistons were heavy and were designed to be used in an engine with an operational rpm range similar to how a diesel engine.

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p173016_image_large.jpg

In the GM part number change book, the 3899643, 67 L88 engine assembly part number was changed to 3819831 in January of 1968.

That part number fits nicely with the new 3819838 aluminum cyl heads that were released at about the same time.


the standard 9.8" deck height on the BBC requires you to make changes,
in some components when swapping to the taller truck block with its 10.2" deck height,
ESPECIALLY if your using adapter plates to use a standard deck intake.
talldeckspacer.jpg

below is the standard intake on tall deck block showing why spacers are required, to allow proper port alignment with the heads spaced further up and out from the crank center line.
After market performance ,big block connecting rods come in several common lengths
0704ch_15_z+chevy_big_blocka.jpg

PICT0496.jpg

PICT0495.jpg


l88kk.jpg

l88kk1.jpg

l88kk2.jpg

l88kk4.jpg

l88kk5a.jpg

l88kk3.png

l88kk6.png

l88kk7.png
 
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