Whats going on guys. Well after a long search on TGO and yes using the search function I am still stumped. I don't have any engine build experience or local expertise in this matter. So I went out and bought a how to build a small block book lol. Anyway I am currently undergoing a full custom rebuild of a 88 Iroc. Plans so far is Holley 950 Commander multi-port, Dominator ecu, GT35 twin turbo, Holley DIS ignition system, 4L80E Trans, TCI Rattler harmonic balancer and a complete suspension overhaul not going to list everything but some basics Ford 9" 350 gears, 4 wheel disc brakes.. And in total with all the other suspension and steering $11,000 so yeah. 16 inch OEM iroc rims, Currently undergoing body work and resto.

So here's the issue I acquired a Gen 1 small block from criagslist and I rolled up, It seemed it has been sitting for some time and was in good condition, so i bought it. I ran the casting number 8970014 yes 8 a weird looking one at that and in comparison I found 3970017 listed as 4 bolt main 70-73 LA built camaro. The Vin reads E (ingraved bowtie) 70. Ok so the odd thing It's a 6 bolt main 2 piece rear seal. I did research and it seems to be a old custom ordered racing engine. Any way important part next.

Currently I have it at a short block stage bored 4.060 383 forged bottom end. now my concern I never built a engine and I can't for the life of me figure out what cam and heads I need for my goal, 1000rwhp street driven. Any specifics you can give me on this I would greatly appreciated!!!!! Please.....
unfortunately I got flat top pistons should i trade them in for dished or will they work?

This is what I got so far

Eagle #356-B12011+060

SB-Chevy 383 2-Piece Rear Seal Balanced Competition Assembly,Bore Dia.: 4.060''
Stroke: 3.750''
Rod Length: 6.000''
Piston Type: Flat Top @ -5cc
Comp Ratio: 11.8:1 w/58cc Head, 11.0:1 w/64cc Head, 9.7:1 w/76cc Head

Kansas car no emission regs

 

that's WAYYYYYYYYYYYYY to much much compression for a twin turbo setup thtere;s a guy orr89rocz on here running a twin turbo setup you should talk to him you need like 8 to 8.5 compression

 

Thanks I'll see if I can't hit him out appriciate it.

 

Never heard of a 6 bolt main block.. what kind of block is that? very interesting to see how that works.

If it checks out ok then you will want to build it as strong as you can for 1000+hp. Thats a good bit over what i'm pushing but my setup is pretty mild. need to find out more info on that block. It may need alittle half fill to be safer, or else if you could swing it, get a Dart little M block.

You have plenty of turbo for that build but need to lower compression alot.

Get some JE heavy duty inverted dome pistons. 28cc or so for 8.8 to 1 compression with a 65cc head. Run a good aluminum head, something like AFR 210's or 220's even. For that much power I'd probably try 220's. Or any comparable head out there in the 215-230 range. may want a 5.7 rod to be stronger but 6" usually better for rpms. Either way it needs to be strong and have good ARP 2000 bolts or even the L-19s.


I'd go solid roller cam for a setup with that much power. You will need some good boost to hit that mark and will need to pull some rpm. Say around 6500 rpm peak, with 20-24 psi. That should do it. Solid roller with its high lift should take advantage of the big heads and really pass some air flow. I'd go custom cam from one of the better known custom cam grinders. Maybe cammotion, Mike Jones who is CamKing over at speedtalk.com, UDHarold over at speed talk used to run Ultradyne Cams and grinds for Lunati, steve morris racing engines, bullet cams, etc. I'd be curious to try steve morris since they build some nasty boosted motors.

You also have a lot of gear. You may trap 155 or more mph which will put you in the mid higher 6000's rpm with a 28" tire. May want to consider a taller gear like 3.2x or so.

1000whp is alot but should be doable on a 383. My setup is a comfy 700whp or so on 14-15 psi. May do more with better tuning but i havent been there yet. thats a 9.8's at 140 mph car full weight and then some.

 

I don't know but it defiantly looks newer and less rusty over the 5th and 6th bolts and the engraved bowtie looks like someone engraved it after production. I am thinking some long ago none existence now, engine guru back in the day ordered the block from GM and did some modifications that he though he could run with.

Wow dude you like pointed me in the right direction after like 3 months of research :bow:
thanks a lot I have some really good base to go off now. I forgot to mention the ARP in the plans I have the internals locked in with the ARP bolt kit that came with the rotating assembly. I will defiantly switch pistons when I get back home. it will take some time seeing as I am not in country currently and will be deploying to Qatar as soon as I get back.
I'll keep this post running with updates and pictures when I get going. And if the block blows heh I can pick another one up. And try again maybe with a Lt1 next time though. but this one really looks pretty solid the same if not more than the dart block

 

Not trying to put you down at all, but an $11,000 budget is extremely tight trying to do what you want to do. I've got $13000+ and I only have mild 400 or so horse power. Good luck though

 

Thats just for the suspension, steering, brakes and rear end. I still got more coming from this next deployment to finish up the engine

 

Ahh, ok. That sounds very realistic then. Its amazing how quickly 10 grand can go when your building a car.

 

And the unfortunate part is it doesn't include labor IE: machining or professional body work Thank the aether for building small blocks for dummies

 

For the most part, I'd agree with a few exceptions/additions:
- that is not a lot of turbo for that power level, as a matter of fact, you may run out with a really well built engine combination. If you haven't bought them yet I would consider slightly larger
- a solid roller is the traditional answer for this kind of setup, but not necessary for the powerband you guys are talking about. You should be able to get into that range with an hydraulic roller if you really wanted to
- Mike Jones is a self important blowhard who can't give a straight answer, and there are much better cam designers out there, like UDHarold...
- In theory, 383 + 24lbs boost + 6000rpm should get you over 1000hp, it seems like simple math at that point, but in reality you're pushing an ugly zone where cylinder pressures are going through the roof and you may never manage get a satisfactory tune and adequately control detonation, and even if you do those pressures will tend to break parts unnecessary. Although, conventional wisdom is that strain on internal engine parts gets greater quickly with increased RPM, you're crossing the line here where spinning more rpm will be less punishing than running more boost, and I would seriously consider building a combination with less boost and more rpm...
- head selection is another place where conventional wisdom won't really work with this thing... don't worry about too much cylinder head boost will overcome the disadvantages of too big a cylinder head, and more head flow will help build the power with less boost.
- ultimately, gears will be decided by the rpm band and tire size, but I'm also guessing that 3.50's will be too much gear also (I've got 3.50's in he 9" for my project and I'm pretty sure that it will be too much also)

 

GT35's are good for 700hp, they are a 70mm unit. It should be enough for his setup. I've seen a few setups with 70 mm units make around 900-1000whp, so it should be enough for a 383.

I like hydraulic rollers myself and thus run one on my car but to take advantage of those big heads, they like cam lift in the .650 range. Hard to get that with a hydraulic roller unless you run a LSx core and 1.7 rocker. But you may beable to get there with a hydraulic roller. I'm pretty sure some of the lSx crowd is there with hyd. roller cam. But solid rollers are just powerful cams, it helps to make as much power as you can on motor so you can run less boost

 

Yes I can see both aspects of that. Realistically if I hit 1000 hp and 800 rwhp I wouldn't be upset and I will probably have it tuned way dawn form that for street application. I was thinking more so engine maxed ready to break under those number. As for the gears I did research and it seems a better gear ratio for street driven with a bullet proof trans in OD and helps with fuel mileage I could be wrong I am no expert in this. I wouldn't want a gear ratio that wouldn't max at 120 mph either I was hoping for a faster top speed and less acceleration. I will probably never drive to the full potential.


So what I am hearing is a smart solution is pick heads like these
http://www.trickflow.com/partdetail....3&autoview=sku
or
http://www.airflowresearch.com/index.php?cPath=24_26
Then call UD Harlod and get a custom Cam hydrolic or mechanical shaft grind to go with those heads and then order the heads to go with the camshaft in case they need to be changed by lift. And maybe go with GT40 turbo's?



The higher RPM thing sounds more solid though after doing more research about this block my wife found some local leads. It seems North Carolina played some influence in NASCAR's foundation and Rockingham raceway was established 5 years after this block was cast both being very close to the area I live, so i am left to believe under speculation that this is a old racing block of some sorts and it kind of makes me want to see what or racing forefathers where capable of so i think I will push this sbc to the absalute limits to see how it holds up and it is a great tribute to history with the restoration in my camaro.

 

There are several guys making 1000whp on Gt35's. I'd use them they are more than enough turbo. IF you wanted that power on pump gas it wont be as easy. LMR built a 402 LS2 motor with twin GT35's and made 1004whp on 19 psi and VP 109 race gas and that is spinning alittle on the dyno. It made 750whp on 7.5 psi on pump gas and probably would push 850+ with abit more boost on pump.

Probably can run a big hydraulic roller and be ok for that power.

I wouldnt use the 227 AFR's as they require offset rockers or lifters and have 60/40 valve spacing which may require special pistons. The comp 210's or 220's would be better choice.

 

gt35's should have a 61mm inducer and 82mm exducer on the compressor wheel
with a Flow Rate of 65lb/min

 

http://www.jegs.com/i/Procomp-Electr...oductId=957641

Would these be the ones your talking about?

 

Your right, i was mistaken. For some reason i thought the were 70mm setups. They are 61's and still good for about 1200 hp on a good efficient setup. 61's are good size for most 383's. For this setup i'd try the GT40 which is 68 mm or so just to make sure you have enough turbo. The 35's will be better when you turn the boost down on the street but either one would work great.

 

Can i request a snapshot of the main bolts? Really, really curious to see this six bolt layout! It's like the jackalope or six legged turkey!

 

Yeah man not a problem I don't think it is anything special just some after cast modification, I won't be home seeing as I am deployed and will be until December. Soon as I get home I'll snap a photo.

 

Are all 6 bolts in a row or do the outer bolts go into the oil pan from the side?

BTW, I take it your in the military so thank you for what you do

 

Actually the set up is the same as a 4 bolt main bit it looks like someone stretched it out a little and inverted some smaller blots diagonally but it looks pretty professionally done