Re: T&D roller rockers, Cam, and Heads
NEVER hurts to optimize breathing before you put a huffer on. Matching components will yeild the biggest gains.
Find a good reputable race shop in your area and have them port and flow-test your stock heads. These heads are not rocket science by any means, a longer version of a 360 head by most respects. The old-school porting methods work well.
A cam and rocker package will also let those new heads suck the air it needs, but a big restriction is still the intake manifold. Your options are somewhat limited right now on this, porting has shown minimal results this far for the money invested. Are you going w/ a Roe system? If so, you need not worry because the stock manifold is no longer used.
Exhaust is only really viable when the engine has a need to expell more gas (thus meaning it is eating more). Finish up your system w/ a 3" pipe free flowing and a set of headers.