Have a 96 GM 350 out of a pickup in my 88 iroc z

problem is that almost every other time i run this car the engine mucks up. no matter what the rpm (only been up to about 4500 on street) every other time i run it it acts like it is going to stall and drops rpm, but always comes back up. this happens at idle, acceleration, decel, and running on the highway 2500-3000. it will do this and sometimes you dont even know the engine is running, then all of a sudden you get powerback and it runs fine for a few seconds and then it does it.

I am thinking that this has something to do with the air and/or fuel becasue those are pretty much the only things that change. The last time i ran it, it was snowing, however, the time before that, it was not. I am assuming it is barometric pressure and/or temperature. I ran it today and it was above freezing temps but still gortex-jacket time! (am thinking it could also be the accell ignition parts

i do not know the exact specifics, but it has edelbrock headers, edelbrock tpibase and runners and edelbrock throttle body mechanism (not sure if thats the exact term, has the throttle plates inside of it though), accel wires and distributor, as well as a hot cam of some sort, nice rough rat idle. not that cheesy bolt on flowmaster rumble as well as some sort of a shift kit and a three nine or four ten rear gear, not sure, dont think it matters.

any help would be appreciated,

michael

(I am really hoping and thinking it is the accel ignition parts - i read of their stuff being 1/3 garbage)