Performer vs AirGap

I think the airgap would be better for a denser colder air charge, but bot the airgap and regular RPM lack a heat riser well, making an engine
tempermental with either one.

Other thing to look at is cost. How much of that is a factor in your purchase? I bought an eddy RPM SBM used, for $100 on evilbay and sandblasted it, and painted it.

How much is a new airgap? VS a performer RPM