OK, here's my problem, when i stomp on the gas the motor hesitates really bad and almost dies and then revs up.

the motor is a 302 2 barrel that came out of my '79 f-100, it's now in my '79 f-150 4x4, the motor always ran top notch. i suspected the accelerater pump but couldn't get it to work any different, so when i happened across a 500 cfm holley 2 barrel for $30 i snagged it up thinking i could get the thing to run right. it didn't make a bit of difference. the carb has a 50cc accelerater pump and #28 acc. pump discharge nozzles, the acc. pump cam looks rather aggressive, this one appears to be red but i can't tell for sure as it looks to be somewhat faded. then i started to think it might be a vacumme leak so i disconnected all the vacumme lines and plugged them accept for the vacumme adv. i then sprayed carb/choke cleaner all around the intake/carb/base plate. so far nothing seems to make a difference. i thought that the EGR valve may have been stuck open and was wondering if i could just block it off and run it to see if it would make a difference, i don't have to pass a smog test where i'm at so thats not an issue. the motor runs great except for when i stomp it all the way to the floor, both vehicles were standard trans also so i don't think thats gonna make any difference. i also checked to see if the vac. adv. diaphram had a hole in it, when i suck on it the advance under the distributer cap moves and if i keep my tongue on the end of the hose it will stay in place so i believe the diaphram is good. i'm at a complete loss at this point. any help would be much appreciated. THANKS!!!