carburetor or distributer?

[aztecworrior]

i have a question regarding my jimmy.. its been acting funny lately. im really confused with the driving characteristics lately.. used to run fine but i had to replace some parts, (edelbrock carb, and distributer internals.)
it will drive fine, then come in and out of power.. (rpms will go up.. down...up... down...) almost sounds like the truck is misfiring.. the only difference is it will only do it iff i blip the throttle while driving around.. very weird.. let me know if you have any ideas.. i thought because it came in and out of power if might be spark.. but, your the experts! thanks!