you might have to change the accel pump cam it may to big we have a 750 dp on a 351 with rebuilt heads 11.5:1 comp, edelbrock manifold, and we had a problem with the same thing and i put a smaller accel pump cam and the problem went a way, a yeah by the way its it a 73 ford f-100 witha c6 and i'v out run a few stang with it