cam question
I dont have any experience with ThermoQuads but I have always wanted to try one. It wont work with a RPM or Airgap unless you run an adapter though. Then it really wont fit under the hood. Also I dont think the air gap is much taller then the RPM.
The problem with the Performer is the port size is for a 318 not 340/360 so its killing some air flow. I think a stock thermoquad intake would give better results then the perf.