okay so i think i have decided on a build for a motor. here it goes tell me if i have anything on here that wouldnt be the best idea or if this overall isnt a good combo
87 roller HO with 48k great running (going to convert to carb)
E-303 cam
1984 351 windsor heads ported and polished but not to crazy of porting. 1.6 ratio rockers
air gap intake (would i be able to use the one for 302 289 or do i have to get a special on if i use the heads?)
if the heads are to much of a pain then gt-40 heads that come stock with that engine. ( getting rebuilt of course)
MSD everything.
holly 600cfm.
would i be able to hit 320 or 340HP?
i have a C4 btw

 

not with the gt40 heads.

you should get 320-340 at the crank with better heads, but not with the 600 carb, you should get a holly street avenger 650. it gives you room for playing around with jets. best street carb imo. we use em all the time on our mild builds.

i made 340 to the crank with my engine.

306ci
edelbrock perf rpm heads and intake
472/496 cam (yeah its small)
forged pistons stock crank stock rods arp hardware
holley SA 650
msd ready to run distributor


i would swap to the 303 cam cause its got a SUPER NICE rumble, but i dont have enough PTV clearance

 

so ditch the 351w heads? they are amazingly worked. new everything and there still in the bag from the machine shop. im only paying 200 for them. and if i were to run them would i have to do anything to make a 302 intake carbed manifold fit?

 

yes dump the 351 heads they are nothing special

get some afr165 heads you will be around 400hp

here is a build you can follow

 

iirc the street avenger is 670 :P

 

Just finished a similar project 302 roller HO out of 92. Used trickflow heads, same cam, and holley 650 (click garage for the rest of the mods), and I put out about 325 to the crank.

 

For that build you could easily run a 500cfm carburetor, 600 will be more than enough. If you get better flowing heads, larger camshaft, etc. then a step up will become necessary.