Well when I look to set up a combo, I start with how big is the motor? OK here it is a 302. Heads, GT40 P likley flows around X cfm at X lift. So then match a cam with that flow and a power band in the rshared_pm range I want to run. Intake will vary somewhat (NA or forced induction).

I ran P heads w/ a "mild" Comps XE264HR. .512 lift was right at where the P's flowed at their max. Idle and vacuum were great. I orginally had a 93 Cobra intake and it all matched up perfect. For a mild DD combo it was hard to beat.

Then I got greedy and added a short runner intake and the Novi and things were never the same. It had throttle response like a damn bike then.