Ok guys heres my deal, i bought a 88 IRoc about 6 months ago, it has a 383 stroker aluminum heads and its carbed. I think the car should run better, I want the car to run low 12s and still have it streetable, I dont really care about HP or torqe numbers just 1/4 and streetable. So What i was thinkin about doin is tearin that down and seein what i can do with it or i got a 400 SBC sittin around needs cleanin and all that i could build a 406 out of and drop in. I have heard overheatin problems with 400CI tho, does anyone know anyhting about that? Would oyu do a 383 or a 406? And in order to get in in low 12's what motor from crank to carb, would you put together? If anyone knows anyone on here that runs a 12 on a carbed motor in a third gen and still drives it on the street, let me know so i can check out there set up, thanks guys.

 

the cooling issues is due to the fact 400's need steam holes in the heads, and head gaskets. If you don't have them, they'll overheat. Otherwise, you're ok. Just keep in mind, your cooling system must support your HP level. A 305 rad and water pump, setup for a 20 year old 190HP car, won't be ok with a 500HP big block (an example). So, keep that in mind.

Since the 383 is in the car, might as well build the 400, if you have the cash to build a 2nd motor, and if you need the car to get you from A-B while you build the 2nd motor.
Otherwise, a 383 would do alright.
off the top of my head, Dialed_In, and IHI both have powerful 383's right now. Many others do too, or have had them.

 

more cubes will make it more streetable with the same combo, not to mention the larger bore will help feeding it. Get steam holes in the heads/gaskets and all will be fine. (should be able to drill them yourself, or have a shop do it) but before you even start ordering parts I'd get it torn down and magged and possibly sonic checked, I've known a few folks with the 400 blocks that have had em come out of the truck and be scrap metal.

 

do any heads have them drilled already? Wahts a good combo for a 406 to run 12's? thanks

 

first things first:

budget
timeline
parts sitting in garage collecting dust that you can/may want to use
90% street, 10% track ok?

 

time line im not really worried maybe this winter or next march or so. budget as cheap as possible but as best and reliable, if i have to wait and save more money for a part thats gonna be better and more reliable i will. 90% street and 10% track is fine, as long as its streetable and runs 12s perfable low 12s on motor. tahnks

 

Before you start throwing a lot of money and parts at the car, how badly is the car running that it should be running better? A 383 with alum. heads sounds like a great engine that should have plenty of power. Is something else going on that you can fix on the cheap?

GM sells a 383 stroker that they call 383/425, as in 383 hp, 425 hp. You already have the 383 part, all you need to work on is the 425. You might want to check the specs on that engine, since you are in the same ball park.

 

i think its compression, i dont think i have enough of it. and it seems to me the guy who put it in before i bought it didnt match parts. We have a cam good 1500 thru 6500, a manifold 3500-6500, heads i have no idea all i know is there aluminum and he says they have 2.02 1.60 valves. and pistons i dont know if there flat top pop up or waht. And the stall i dont know for sure either. I thought about just fixing this one but i dont know what needs done without tearin it down. and i need a driver still so i figure i could build the 400 have more cubes get more power know exactly whats in it, and still have somethign to drive.

 

big *** radiator takes care of the 400sb heating issues

i have a 400sb original to my '77 Cheyenne K-10 full time 4x4 pickup and is still in it with normal everyday stock steel blade clutch fan and all and i drive it daily in the 90's temps heat thats been here and no issue whatsoever at all, and i drive it kinda hard too, but then it has a factory 4 core radiator in it, but the shroud is broken and missing a big chunk in the lower left side

but still..

runs normal temps around 195 all the time perfect


i dont see any big heating issue with them from personal experience

unless there was something bad wrong with the radiator or waterpump or something


these 400 engines have some real nice lowe end torque i tell ya what, evne jut the 280 net torque this 77 truck 400 has is nice, it will roast the tires on this 4x4 anytime i want to, on pavement
but i have only done it three times ever, and not for very long, no smoke, no leaks or anything at all ever




good luck

 

the key to building 400s is good heads. dont even bother with the factory ones. give AFR a call. or check out brodix. you really shouldnt have a problem getting 12s out of a 383. those are pretty stout motors.

 

Yea i just think that i kinda made up my mind on the 400 i mean i have it i might as well use it and its more cubes. Heads i have no idea waht to run.What do you guys suggest. I found some "world" aluminum ones in summit part number WRL011150-2 assembled and all for $959 is that a good deal, and are they good heads? Thay say they produce awesome low end torque which is what i want for street driven car and still run 12's, What do you guys think of them heads?