My Swap Plan (comments welcome)

[Shon]

I want to do a 243/Cathedral port vs a LS3/retangular port comparison but the problem is the LS3 style really needs a different cam too so then you run into lots of variables trying to compare the 2 on the dyno and track/MPH.
As I have mentioned before, 2 GTOs with nearly the same mods making nearly the same power at the wheels. 243 headed GTO was showing 2+MPH in the 1/4 on same day same track.
One thing that lots of people do not factor in with the LS3/L92 heads which Clown mentions is the intake design is different plus factor in the rocker arms that are needed, it adds into the cost if you already have cathedral heads.

Just plan it all out before you move forward but the motors can make power and useable power in all the RPM ranges.