i have a 283 with 041 heads, 2.02/1.60 valves, .422 .444 lift 204 214 duration at .050 cam. it is a 67 2 bolt, i think it has the stock cast crank. i was told buy a guy when he looked at the rods that they were shot peened. it has .030 over pistons, i don't know if there stock or not. what is the highest you think i should rev it safely?

it has a cc q-jet on it right now that the mc selenoid isn't working so its dunping a bunch of fuel in. but if i floor it for about 1.5-2 seconds it pulls the secondaries open almost all the way at about 4000 rpms. i don't know if i should get a 600cfm or more if i get a new carb and intake.

right now it has the stock manifolds from a 305 on but i have the headers in my garage, i just need to get a y-pipe made. how much difference do you think they will make?

 

I'd estimate 20-25 hp increase with the headers.

 

no 283 had a cast crank from the factory. with the mods and all i'd guess you're in the 300 hp range at best, but you'd need to provide a few more details. more than likely your max rpm will be limited by air flow and not mechanical strength. you have better heads than you need right now. as far as mechanical limitations rod bolts tend to be the weak link, at any rate 6 or 6500 would be the extream top limit. you really want to stop spinning it after you reach the torque and hp peak.