stevo9486

Ok i have a 94 Z71 5.7..im rebuilding the motor and im going with double hump heads with 2.02 valves and boring it .30 over. stock cam (just bought it) stock intake (thinking of going with a edelbrock) new stock lifters, and stock tbi unit. what hp can i expect from this or any opinions on wat els i could do?

TexasSam

I would put Vortec style heads instead of the camel humps. The small chambers on the humps will increase the compression and may cause valve rattle unless you run 91 oct. fuel. As far as HP gain just changing the heads and leaving everything else stock won't do much. Finding a good combo ....cam,intake and heads will get you the best results.

greddy

your really limiting yourself with that cam if your looking for power, and the stock intake doesn't flow very well compared to just about any aftermarket intake. A good friend of mine has a 94 chevy 2500 2wd and he rebuilt his 5.7 and made a 383 stroker with a roller cam conversion, stock intake, stock heads, and some shorty headers. the stroker kit made a huge difference in torque and he uses the truck to pull a 32 ft fifth wheel, before it use to struggle now it's easy as cake at any stop light.

If your looking for a good daily driver motor that still puts down power and does it on 83 pump gas. do a mild cam swap, aftermarket intake for a cheap budget build.

If you have a little more money to play with, do a stroker kit, with a mild retrofit hydraulic roller cam, new aftermarket heads and intake. new pushrods, rocker arms, and lifters and you got yourself a nice little street motor. The stroker kit will most likely raise your compression ratio a little bit depending on how you build it, so you could probably get away with running 83 with a little octane boost so it doesn't knock. with the right timing id say 15mpg and anywhere from 300 to 450 hp is possible with that setup.

with the setup you got going now, with a stock cam and vortec style heads id say you might get 260 - 300 hp. stock hp on that motor was said to be 260 and without changing the cam your really leaving that number linger in that range.

stevo9486

yeah my deal was that me and my buddy were rebuilding it and some how one of the pistons got swapped out plus he put the timming gear in wrong so it never cranked...so i pulled it back out..tore it down..bought new pistons (.30) turned the crank .10..from the beginning i was just going to rebuild it stock..but now its gotta be redone so..as far as mods all i have is .30 over pistons. im thinking about going with a set of headers. yes i wish i had the money and i would go 383 but since ive built this motor TWICE im kinda pissed so im just ready to drive my truck again haha

2wd-K5

honestly i dont think you wil gain anything at all. the camel hump heads will run dirtier, so the comp will lean it out, and the compression will be higher so the comp will run the timing more retarded, as for heads, you will gain more power by putting the old ones back on after you do port matching and a cleanup, or a few hundred can get u a set of vortecs, and sell the double humps for the same price

stevo9486

yeah its all built and put back in the truck now..drove it today..im probably going to look for some vortech heads later on.

stevo9486

It has a little miss to it...but its only at idle. it will die if it idles over like 45 secs. it smells like its running rich. would boring it .30 over cause this?

2wd-K5

no, the heads will make it smell rich and wont run 100% with them, they put out a lot of pollution, and the comp cant keep up so it throws it into limp mode, and it will most likely chug fuel too
vortec heads will solve it, as for the miss it could be many things, go over your ignition system, plugs, wires cap, rotor

stevo9486

another question..would a broken head bolt cause a blown headgskt? orcause water to get in the oil? and im speaking of the lower side bolts...

2wd-K5

yes it could, while the heads are off though, i would check the cylinder walls for cracks as this usually is another reason for water in the oil