standard performer rpm has the same square bore mount as the performer,there the same.you have to get the performer Q-jet spread bore intake to mount a q-jet,or put a adapter on the regular performer.if you could bolt a q-jet to a regular square bore intake(wich you cant)you would have one massive vacuum leak at the sides of your q-jet.square bore(holley/carter) is wider then spread bore(q-jet and the older carter afb's)
if i'm wrong someone please correct me!!!!!
but i'm sure i'm correct.although i've been known to be wrong once or twice.
shane
