Building a S̶t̶r̶o̶n̶g̶ ̶3̶5̶0̶ 383 for Frank the Tank…

Discussion in 'Engine Combos and Dynometer Database' started by JimmyDuncan, May 1, 2015.

  1. JimmyDuncan

    JimmyDuncan Well-Known Member

    Welcome to my build thread!

    My name is Jimmy...

    I’m typically a lurker on forums, usually read it all and keep quiet. But I’m 100% sure that I’m going to need a lot of support in the endeavour to rebuild my first 350 engine, to go in my 66 Impala (named Frank the Tank by my 6 year old daughter..). So, I figured I had better introduce myself and get amongst it all.. :)


    Frank is a Turquoise (with original patina) coloured 1966 Impala 4 door pillarless. Currently sporting a 307, possibly out of a pickup of some sort and a 2 speed powerglide, Frank is a cruiser at best… The radiator has been reconditioned, the brakes have had work and stop when required, new exhausts have been fitted and new shock absorbers fitted. Frank is in need of a bit of remedial work, as there is a serious bog if I try to accelerate quickly and there are strange clanks underneath on the odd occasion, maybe related to gear changes or drive line… I’m pretty sure the 2bbl Rochester isn’t doing me any favours either…

    I recently bought a recently running, built sometime in the 70s, 350 engine (3970010) and TH350 transmission… (the engine is currently nicknamed “Grimy”). I think they may have originally been out of a Camaro. The plan is to rebuild both and install them in Frank the Tank.


    I am thinking that in the short term I might service the TH350 and fit it in to Frank soon. This may help the 307 get us cruising a little faster from the stand still. Then over winter I’ll rebuild the 350 and hopefully have it in and running for summer!

    My goal for the engine and for Frank is to get to a point where I can challenge my Dad’s 66 Turquoise 2 door Belair (Franks cooler cousin) over the ¼ mile. He’s got a big block and a manual transmission, and more funds… He’s gotten close to 13 flat for the ¼ mile, which I know isn’t that fast, but I would like to just beat him… (Beating dad has always been a motivation for me… he still has the family half marathon record…. But I’ll have that this year too….) So, using the calculators online, to get my approx 4000 pound loaded car to go 13 seconds flat, I’m after 360hp…? But, for some reason 400hp sounds good…. Hopefully I can get that with this 350 and then once I have the experience under my belt, I’ll look towards a big block…

    The budget is limited, a ball park figure of $2-3k. Parts are more expensive here in Australia, so I’ll need to be efficient… The more I can do myself (within reason), the better. I will need to buy and borrow some specialist tools and order parts over time. I am in it for the experience and the outcome...

    I have initial thoughts on what new parts will go into the build, but I’m relying on you guys to point me in the right direction for a build that will be reliable, fun to drive and go quick when asked to.Feel free to spell out the specific parts... :)

    I’m looking forward to hearing what everyone thinks…
    Last edited: May 5, 2015
  2. grumpyvette

    grumpyvette Administrator Staff Member

    well on the plus side youll have a bit easier access to the engine , when you install it, due to the larger engine compartment, but 4000 lbs is going to takes a significant amount of torque from a small block to allow it to compete with a big block car, thus Id at least consider a 383 stroker kit as the over all cost will most likely not be all that much more if its done correctly because even if you rebuild the 350 its highly likely the bearings, rings, connecting rods and pistons will need to be replaced and the crank polished.
    keep in mind that use of a decent set of high flow rate cylinder heads and a low restriction exhaust will allow you to use a noticeably lower duration cam and still make impressive power if you have decent compression.
    your selection of cylinders heads and matching intake are a major factor in increasing the engines power potential, and selecting and properly installing a properly matched cam, compression ratio and drive train gearing also will play a huge role.
    due to the application and your choice of automatic transmission youll want to concentrate on mid rpm torque, and the rear gear ratio and converter stall speed used in that heavy car will be critical in getting the power band to match the need to quickly accelerate.

    Last edited by a moderator: Jan 10, 2018
  3. grumpyvette

    grumpyvette Administrator Staff Member

    notice the difference in cost between the 350 vs 383 kits

    you can certainly get a decent cam, but knowing the heads and your gearing and converter stall will all be required to select it correctly

    decent heads are expensive but scrimp too much here, and your choice comes back to bite you in the ass, restricting power significantly, trust me youll regret not getting the very best heads you can afford,and your effectively killing off much of your potential, as a general rule you spend 40% of the total on the heads, if you realistically expect to beat that big block youll need good heads and while ported stock heads could produce decent numbers they are hopelessly out classed by the better mid cost aluminum heads available
    a basic build

    380 cu in vortec head build
    heres a mild high torque build using a set of mildly reworked vortec heads and a chevy hot cam.

    If your going to run vortec heads, you either check you have clearance on current heads, with accurate precision tools and/or if you find you don,t have the required clearance,your going to be forced to modify current heads or you could buy heads with the correct clearance

    reading the related info will be helpful
    Last edited by a moderator: Feb 20, 2016
  4. Indycars

    Indycars Administrator Staff Member

    Very nice opening post!!!

    It's going to be very close to reach your goals with the budget you have. The heads and rotating assembly will cost $1800 to $2000, not sure how much shipping is going to factor into it. You might try Summit and put the rotating assembly in your basket, then you can estimate shipping without going thru the whole process.

    First thing is to get the engine disassembled, then take the block to the machine shop and have it cleaned and magnafluxed for cracks. Need to see what we have to start with.
  5. DorianL

    DorianL solid fixture here in the forum Staff Member

    Agreed. Damn I wish I had a pair of heads to send you. And agreed with the above, a 383 would be a good idea for such a heavy car.

    What 1/2 marathon time are you shooting for?
  6. JimmyDuncan

    JimmyDuncan Well-Known Member

    Yes, there's plenty of room under the hood... The weight I found online was 3,535 lbs and adding 190-200 lbs for me, maybe its closer to 3,800 give or take. Not sure if that makes a difference, but, yes, Frank's a heavy-weight... :)

    I have considered a 383 build, but, I was under the impression it would require more $ and more skill on my part....? I'm not against it at all, I was just trying to set my sights lower and maybe building towards a 383 (or stroked big block...) in the future. I'm anticipating that I will require new bearings, rings, connecting rods and pistons. I'm reading How to Build Max-Performance Chevy Small Blocks on a Budget, and it looks like it's probably a good idea to replace the crank..? So, you're probably right....

    I have been studying up on cylinder heads and plan to pick up a set of something like the IK200 (depending on what you all think..), but if there is a equivalent option that's better value, that would be great. Value for money is going to be an important factor throughout this build and I'll have to make quite a few compromises. I was thinking a Performer RPM or RPM Air gap for the Intake...?

    I tried to find out the rear gear ratio last night after I found out that a code should be stamped on the passenger's side of the housing. But, I was short of time and all I achieved lying on the garage floor was sprinkling dirt and grim in my mouth and eyes... I'm going to have to get some soapy water on it first... But, I'm thinking I'm going to need to upgrade the 10 bolt rear-end with something more hard wearing..? So I can select gears to match the engine and trans rather than build the engine to match the rear end?
  7. JimmyDuncan

    JimmyDuncan Well-Known Member

    Thanks Indycars.

    Yeah, I'll look into shipping costs a bit more and see what they'll sting me for.... I think I'll still be ahead compared to paying Oz prices... The selection will be better too. Do the big online stores have specials often?

    Yep, engine disassembling is going to happen soon. Before I start, knowing that I'll likely replace most of the internals if I want to reach my goals, what do I need to be looking for or measuring as I pull it down?

    I need to find a good machine shop near by, so I'll try asking on a few local forums for suggestions... I don't have a good car guy network here yet...
  8. JimmyDuncan

    JimmyDuncan Well-Known Member

    Thanks. I wish you did too Dorian ;)

    I'm hoping where appropriate I can pick up some parts used or on special... But only when they fit the plan... I've heard loud and clear about the risk of buying parts at awesome prices that are not appropriate for the build... I won't do that..

    Hmm, I'm feeling the peer pressure to go 383.... Which would be awesome if I'm honest.. :)

    Well, Dad has run a 1:27:30 or so and my fastest which was a little while ago is a 1:28... I want to go 1:26 to make it clear who is fastest... ;), which I am pretty sure I can do if I just focus on running for a while.. I'm a good 10-12 kgs (25lbs) over my Ironman race weight (which I have hit a couple of times in the last 5 years), so I'll lean down and do some solid running and take out the 1/2 marathon and 1/4 mile records in the next year or two :D
  9. JimmyDuncan

    JimmyDuncan Well-Known Member

    I got a Quadrajet (17080513) as part of the purchase of Grimy the engine..


    Is it worth rebuilding for the project? Or no?

    I also considered rebuilding it and putting it and the intake off Grimy onto the 307 for a little more performance over winter... But, maybe that's just $ and time wasted flogging a dead horse..?
  10. grumpyvette

    grumpyvette Administrator Staff Member

    a weekend spent reading the links and sub links, posted here will be very very helpful
    don,y get over whelmed like eating an elephant, its simply a process of one bite at a time, and not rushing while you chew thru, and digest the info and if necessary ask questions

    the cam rotates while indexed by the timing chain at 1/2 crank shaft speed , there are connecting rods designed to provide additional clearance.
    don,t forget to verify the cam to connecting rod clearances
    a cams VALVE LIFT is determined by the DISTANCE the lifter moves as the cam rotates under the lifter base as it moves from the cam lobe base circle
    (the closest the lifter comes to the cams center line)
    up to the cam lobes ramp to the lobes peak,
    (the furthest the lifter up off or from the cams center line)

    your cams lift, is the result of the lifter movement, or distance it travels from the cams base circle, where the valves seated, to the point in the cams rotation where the lifters moved along the ramp surface fully up on the nose of the cam lobe where the valves at full lift.

    lets say in this case we compare two imaginary cams
    a standard cams base circle is 1.125" and
    your cams running on a .900 base circle
    both cams have a .560 valve lift and run with 1.5:1 rockers
    so both cams will need to move the lifter .374"
    that means the standard cam lobe will be 1.125"+.374" or 1.499" from the cams base to the cam lobe nose
    that means the small base cam lobe will be .900"+.374" or 1.274" from the cams base to the cam lobe nose
    which is significantly smaller,
    small base circle cams are generally only used when connecting rod clearance necessitates there use



    the BASE CIRCLE IS NEVER A CLEARANCE ISSUE, its the cam LOBES that can potentially contact the edge of the connecting rods or bolts, this is why the rods or rod bolts are machined for additional clearance for the cam lobes as you rather obviously CAN,T machine the cam lobes themselves without destroying their function.
    now think about it for a few seconds

    the cams lobe lift and the cams LSA or LOBE SEPARATION ANGLE
    both have an effect on the cam lobes potential interference with the connecting rods
    notice how the rod bolts come close to the cam bearings as the pistons reach top dead canter in the bores



    rods designed like the 3 SERIES generally won,t work with stroker cranks while the 2 series usually will

    the connecting rods you sellect make a huge differance in the rod to cam lobe clearance, even a small base cam won,t clear some designs, it should be obvious that the connecting rod with the thru bolt has a great deal less cam lobe clearance potentially than the cap screw design next to it., and the cap screw rod probably clears the blocks oil pan rail area easier also
    Last edited by a moderator: Feb 16, 2016
  11. JimmyDuncan

    JimmyDuncan Well-Known Member

  12. DorianL

    DorianL solid fixture here in the forum Staff Member

    Holy Crap that's fast!!!!!! You, not (yet) your boat.

    Tell your dad it's a 3-oh-why when you're done. :D
  13. grumpyvette

    grumpyvette Administrator Staff Member

    keep in mind the drive train gearing and transmission converter stall speed, and matching the cam,compression ratio, and matching the heads and intake used, is important, yeah!
    you can install a killer cam that could potentially make a good deal of peak power, but its likely to kill power brakes and make the car run like crap below 3500rpm, so theres ALWAYS going to be compromises.
    yes you can make very impressive power from a SBC, but its the TOTAL MATCHED COMBO not an individual part that makes the engine run well.
  14. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

    think it through! you can build a very impressive 383 sbc and we can supply you with the list of parts but as always the list of what you can afford to do,and what you want, to do, will vary a bit so compromises will generally be required.
    youll also want to consider the fact that an engine that makes a good deal of power at 6500rpm that might easily show your dads big block powered car its tail lights, will by design be rather less than ideal on the street in traffic if your cruising along at 1500 rpm, so there's always some priorities to be discussed and choices to be made.\
    EXAMPLE, if you have a 3000 rpm stall converter and a 3.54:1 -3.73:1 rear gear ratio you can run a good deal more duration in a cam that a similar car with a 2.87:1 rear gear and a stock 1800rpm stall converter, but the longer duration cam will reduce the engine plenum,vacuum the power brake booster sees
  15. JimmyDuncan

    JimmyDuncan Well-Known Member

    Ha! Thanks. Yeah, my boat is not fast for sure...
  16. JimmyDuncan

    JimmyDuncan Well-Known Member

    Yes, thanks Grumpy. I hear you, that to build a car that shows up my Dad, I might end up with a car that's not pleasant to take the kids for a drive to the beach in... At the end of the day I'm going to very rarely go flat out in Frank... So, performance within reason, with a focus on durability, budget and drivability are my main goals... I could live without going low 13s... :) but, I'd like to see how close I can get with what I can put together.. :)
  17. JimmyDuncan

    JimmyDuncan Well-Known Member

    So, I get it that I will need to replace the 10bolt, unknown gear ratio rear end (and possibly the tires also), to get anywhere near the strength and performance required to match my rebuilt engine. With that in mind, and not building the engine to work with those current weak links, what parts list do I need to start thinking about for the engine rebuild..?

    I'm starting to piece together a draft list, keeping in mind, I need to strip down Grimy the sad 350, before making any purchases (please feel free to point out any errors in my plan so far, because I'm hoping to learn and trying not make costly mistakes...:) )

    SCAT Series 9000 383 rotating assembly - Which grade? Cast - Pro-comp? Internal or External Balance? 6" rods ?
    Brodix IK 200 Heads look good, but maybe too big? but I'm open to other options that are similar but better value.. Performer RPM?
    Edelbrock Performer RPM Airgap intake - Or will the RPM do it?
    Holley 750 with vacuum secondaries?
    I know a roller cam will be better..? is it required? What's the difference in cost? versus value? If not much difference then a flat tappet. I'm still struggling with making the link between other parts and choosing cam specs... but, I'm thinking once I have the engine block ready and get other parts then it might start to make more sense when I can take some measurements then choose the cam?
    1.6:1 roller rocker?
    Larger oil pan and upgraded pump.

    Which parts is it safer to buy used? I ask because I have seen a few used Performer RPM intakes online... But, if the Airgap is more preferred, then I'll let them go.

    I really don't want to just ask for the answers, but, I also need some options and whys, to see if I have picked up what all my reading has said... If that makes sense...

    Input welcome :)
    Last edited: May 4, 2015
  18. mathd

    mathd solid fixture here in the forum

    Welcome :).

    Here's what am thinking for the street.
    internal balance 383, 5.7" rod. (i know everyone will tell you 6" rod internal balance)
    Can't help for head and intake. 64cc head 383CID assembly above = 10.7:1~ CR with standard FELPRO gasket and some decking of the block.

    Holley 650-700 CFM, everyone oversize carburator..
    If you can afford it go roller cam with synthetic oil(once the break in's complete). Better durability(or peace of mind) and roller lobe ramp are steeper for more flow/performance.
    Am not a fan of higher ratio rocker... Just get the correct lift/cam.

    I think a cam with about 225-235 duration 110 LSA and around 0.500 lift.
    and then match the rear gear ratio and torque converter to that.

    The 10 bolt rear should hold up to a 13 second car. .. ok maby am dreaming there but worth a try.

    Thats what you need to focus on right now :
    Get the engine block prep and ready(especially before ordering the rotating assembly"piston/bore size!!!").
    Eagle 383 rotating assembly, ACL bearings rod and main probably (5M909-H and 1B663-H)
    High volume oil pump with HD shaft, pump pickup, bigger capacity oil pan, windage screen/tray and plastiguage, Full gasket set(fel-pro).
    What block your using? 4 bolt main, 010? (just curious)
    Last edited: May 4, 2015
  19. grumpyvette

    grumpyvette Administrator Staff Member

    Id say step one is verify your current rear gear ratio and what rear differential you currently have installed, clear pictures of the differential will be very helpful here! and put the car up on a couple jack stands, so both rear wheels are free to spin, off the ground, and mark the drive shaft with chalk or paint with a clear line and put a index dot or bit or tape on the rear wheel, now pay close attention, spin the rear wheel slowly and see if the other rear wheel spins in the same or the oposite rotational direction, then count the times the drive shaft rotates in a single rotation of the rear wheel.

    ID also point out that measuring the rear differential width is very helpful as theres sure to be far stronger rear differentials with similar dimensions and if you have access to a salvage yard and a welder and some fabrication skills finding a replacement rear, having a similar width or a bit narrower to allow a larger and wider tire (ideally with DISC BRAKES )and a stronger design, like a 12 bolt, ford 9" or dana 60, or pontiac 9.3" that can be installed without a great deal of extra effort, other than fabricating the necessary brackets for spring and suspension mounts and matching the drive shaft u-joints and length, that you can purchase reasonably may be a very worth while option
    yes sounds like a lot of work and expense but its generally something most guys can do or have done reasonably in expensively if they get a good donor car and have a welder ESPECIALLY if you have several helpful and experienced local friends, (this is a great reason to join several local hot rod or corvette clubs as theres always about 10%-15% of the members in most clubs that have both skills and tools that may be willing to help on projects for far less cost than a custom shop charges... and it sure helps if you know what your doing and how to accurately measure, so the works done correctly, (this takes research time on your part!)
    Last edited: May 4, 2015
  20. 87vette81big

    87vette81big Guest

    Try and follow Grumpys build recipe and advice.
    Your not all out drag racing.
    They do have a limited life before rebuild time True Racers.
    10,000 miles is what I can get from Race 455's. Better than most can do.

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