1988 iroc..engine is a 4 bolt main block, scat crank, pm rods, hypereutectic pistons, 383 cu in., edelbrock 60cc performer heads, edelbrock tpi system, comp cam roller rockers, comp cam, polished tall valve covers. All accessories are there except smog pump. New power steering lines, alternater, starter and battery. Engine is fromm enginefactory.com I want something that'll put me in the 400-425 rear-wheel horsepower. any suggestion or setups? 4 Bolt Main, Full Round Seal Block New Scat CS383 Crankshaft PM connecting rods H860CP Hypereutectic Pistons Sealed Power Chrome Moly Rings Heavy Duty Double Roller Timing Set Aluminum fast burn Edelbrock 60cc Chamber cylinder heads #60859 with stainless steel valves, hardened valve locks, chrome moly retainers & HD Valve Springs Matching Comp Roller Camshaft Comp Cams Hydraulic Roller Lifters Federal Mogul Tri-Metal Bearings New Comp Cams pushrods Comp Cams Roller Rockers Edelbrock Intake Base Plate and Runners Manifold #3890

One of the bottlenecks will be the Edelbrock TPI manifold. I have mine Extruded Honed and I'm running out of air at the 350rwhp mark. To get to 400rwhp you are going to have to get the runners in the manifold opened up.

Not sure on the Edelbrock heads you have but they need to flow somewhere in the 280cfm range if not more. If you are serious I would send the heads and intake manifold off for professional porting.

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To be honest you are not going to make it with those parts. The number one thing is the heads. They don't flow enough cfm to make 400 to 425rwhp. I don't think they are a good choice for a 383.

Next up you did not state what camshaft your are running. You will need a good modern camshaft with at least 230 degrees on the intake at .050" and a lot of lift. A little bigger would not hurt.

The Edelbrock TPI intake manifold will need a lot of work to flow the numbers required for what you want to do. It can be done just money. The crux will be the runners. I don't know of any you can buy that will support that kind of horsepower. SLP's might but will require a lot of work. Your Edelbrock runners might but would also require a ton of work. The factory plenum will work with modification. Maybe a Holly Stealth Ram is in order.

I would want to use a 58mm throttle body. You will need a first class exhaust system such as Dyno Don's 1 3/4" headers, wye pipe with dual cats and a good cat back system.

Don't know what your cold air intake is like but you will need a good one depending on whether a Camaro or a Firebird.

With a 700R4 I think you will need 500hp at the motor to achieve your goal. You will need a good selection of parts and proper assembly.

yeah, i've since posting this up months ago came to realize this isnt ideal, more like 425HP at the flywheel is what i am aiming for. and i want to use a LT4 hotcam in my 383 stroker. any ideas or thoughts on how i can reach that using the edelbrock intake and runner combo with a ported plenum anyone?

my thoughts...

Those heads are not much better than L98 aluminums but STILL can make 425hp on crank so your good IF everythign else is right

Flat top pistons and 60 cc heads = WAY too high compression... roughly 11.6 to 1. 2 options..... ditch the heads or ditch the pistons for dished. MAYBE a third option is to have the heads ported and possibly opened up to 65-67cc or so. that be more doable 10.8 to 11 to 1 compression range

hotcam MAY be enough cam for that motor with a fully siamesed/ported TPI setup to achieve 400-425 CRANK hp. I'm thinking thats roughly 330-340 at the wheels. Hotcam 383's have hit 370-380whp with GOOD heads and intakes like miniram/carb manifolds/ or HSR. Else step up to the 230/236 XE grind or CC306. That should easily put you there with those heads IF you keep compression to 10.5-11 to 1

appreciate it. Thanks You