will Air gap RPM manifold fit ???

The factory 4bbl. You have is the second best next to the TQ intakes. The factory intakes are no slouch's. The RPM is worth a fair amount of power. How much depends on your build. So if I said it was worth 20hp, I could be 50hp off of the bud was getting serious.

This is a little beyond there useage and intended range, but.....
Stock intakes have powered cars into the 12's. FAST cars run low 11's.
You'll find more of a E.T. Gain at the light than you will with an extra 50HP up top. You can do more with less of the car can hook and book. Read sig below...