Ok so my 305 is out of the car again and I'm gonna do a few things to it before I put it back into the new camaro. I want full roller rockers, a different carb type intake manifold, and I'm gonna port my 081 heads and gasket match everything. Ive picked out a few things and want some opinions.

roller rockers
http://www.summitracing.com/parts/PRO-66915/
intake manifold
http://www.summitracing.com/parts/HLY-300-64/
head gasket
http://www.summitracing.com/parts/FPP-1094/

Already have
http://www.summitracing.com/parts/CCA-08-500-8/ CAM
http://www.summitracing.com/parts/CCA-981-1/ Valve Springs

Motor was rebuilt 50K ago with new everything. I have flat topped pistons with valve reliefs so I don't think the 1.6 ratio rocker arms will be an issue. I have heard that I will need slightly longer push rods with the 1.6 ratio rockers arms but couldn't really get a yes or no answer or what length they need to be. Im also worried that the valve springs may bind and that the heads will be over their limit for lift.

 

You don't need longer pushrods because you're going with 1.6:1 rockers. I haven't heard glowing reports about Proform Al rockers (used to say "for stock lift only"). I'd pony up the extra bucks and get Comp Ultra Pro Magnums instead.

You would need to modify the heads with 1.5:1 rockers, so, yes, you'll have to cut the guides to use that cam, 1.6:1 rockers, and those springs. The springs should be fine with the lift if installed at 1.7".

 

competition products sells some Scorpion rockers that have a lifetime guarantee, and unlike the COMP's that kid suggested, these are $210 / set. But these will require guideplates if your heads have round pushrod holes. If your heads have slots for the pushrods, then COMP's "Louis Tool" will let you elongate them and use these rockers.

 

That cam is really small, are you going more for torque? If you're goin with a carb manifold, do yourself a favor and go with the Edelbrock performer rpm air-gap. They flow really well up top and give a lot of mid range torque. Smaller engines need to rev to make power because they just dont have the cubes. I know you already have that cam, but I would suggest going with something around the 224/230 range. One of my 305s I built was running mildly ported s/r heads, 10.1 comp, rpm air gap manifold, holley 600 vac sec carb, 224/230 dur .502 int .510 exh 110 lobe sep. 1.5 roller tip rockers, I made 298 wheel horsepower through a 700r4 trans. that was a fun setup. i tried 1.6 rockers and never got positive results in a 305.

 

No, don't use the RPM AirGap with that cam and those heads on that engine. It's a definite mis-match. If you want an air-gap, Edelbrock offers a Performer AirGap that isn't the RPM, but is for '87-up heads. That'd be a fine choice.
A 224/230 cam is going to have a 305 making power past 6000 rpm. 1.6 rockers actually hurt above 5500 rpm. This tiny cam won't get you to 5500, so go ahead with the 1.6s if you want.

 

I used to have the reguler performer manifold on it and switched to the rpm air gap, it increased mid range torque and hp a lot. And no, it does not make power past 6,000 rpm. The peak torque was 290 at 4,500 and peak horsepower was 298 at 5,900. Just by adjusting the timing a little and switching manifolds i went from 278 to 298. I have the dyno sheets to prove it. It was a fun motor for its size. But I do agree with you on one thing, the stock swirl heads would be a mix match. LIke i said earlier, I had mildy ported world products S/R heads. That makes a big difference.

 

I dont think I mentioned that I will be running the TBI injection on this motor and not carbed. I wouldnt want a carb on any motor and yes it will at some point get tuned or converted the mass air flow later down the road. I dont plan on changing the cam since it will be computer controlled and just want a little extra lift out of it. Im really just trying to free up some ponies with the roller setup. If it really wont get me anything tangible than I will put the money elsewhere. I also understand that the AirGap manifolds are not good for TBI injection as the fuel can deatomize on the manifold walls and cause issues. I would also like to keep the stock hood since I have a factory fiberglass hood from the early 80s. This motor with only a cam and headers ran 14.8 at the track in my previous car and reved to 6K no problem. Actually broke a valve spring racing an STI cause i reved her too high. Id like to knock that down by another second with more powerful engine and lighter chassis. Suggestions?

 

Well, not with stock heads, but noone would try that big a cam with untouched heads. And the World 305 Torquers still have worse short turns than 416s. It's fairly easy to improve the exhaust ports of those Worlds, but the intakes aren't very responsive.

 

Full roller 1.6:1 rockers are worth doing. but they're not gonna get you another second. Maybe 15% of it. That's what a 100-shot of Nitrous is good for.
A cam swap would get you there, and still be computer friendly if you pick the right one.
If you still won't consider changing the cam, and if you won't use Nitrous, then you're gonna need better heads, or a 350. Or an awful lot of chassis work.

 

Im considering nitros later down the road too but im not building the car for straightline drag racing and need that power there teh whole time. Does anyone have any other suggestions on intake manifolds. The TBI guys on this site say the weiand manifolds are the best. opinions!