i have an 84 z28 with a 283 in it right now. the 283 has 041 heads, about 9:1 compression, a melling cam with 204/214 duration and .422/.444 lift, short tube headers, performer intake and 600cfm carb. i just got an 87 roller, 4 bolt 350 and i'l probably put that in with the 041 heads, about 9.5:1 compression, a comp roller cam with about 210-220 intake duration, and the rest the same. how much more power do you think the 350 will have? the 283 is already pretty quick and will destroy a stock 305. thx

 

Well thats a 67 cubic inch improvment. As far as a power estimate ????????????????????????????????????? no one can say for sure but the 350 is a better platform to work with and will be more responsive to modifications.

 

Engine rebuilders who put together a combo like that usually advertise it at about 320-330 hp. You'll probably want to use dished pistons with those heads, with flattops the CR will be over 10-1 ...too high for those heads. KB 193 is a good choice.

 

Keep the 283 and put in a 327 crank.

 

why? that'd pretty much make a 307, an attorcious motor unmodified. it'd be better to take the 283 crank out and put it in the 350 (if it'd fit) and make it a 302 if you want a small displacement powerhouse. Bore the 350 out .030 and make it a nifty 355 with vortecs and a solid cam. or slightly stroke it to a 363 like me and run low 11s with the right stuff

 

what kind of power do you think it would make with vortecs, a little under 10:1 compression, and a roller cam like the comp XE(i forgot what one exactly but maybe the next one up from the biggest with stock converter)? do you think it would get between 350-400?

 

You would be lucky to get around 300 crank hp 350cu with the mods you selected. You would be way better off digging up a 400 and building it. More cubes make more power easyer and with less fatuige on the engine. I dont think anyone around here has used vortec heads on a 400, you could be the first.