Engine starting and running troubles..

hi there once again,
i took my car out the other day, it started fine, and ran fine for about fifteen to twenty minutes, then she started to pop/ping in the the exhaust, and would die if the revs were below a thousand rpm, to get it started i had to crank and crank and crank and finally with the throttle wide open cranking it would start, i would hold it above a thousand throw it in gear and fight with it to keep the revs up and she would stutter pop bang ect.. i finally got it home and swapped the points out and threw my electronic ignition back in (b.t.w i rebuilt my points distributor and reset point gap ect.. and previously swapped out the coil for and accel) pulled off my 600 eddy and trew on a 650 holley double and ran her the next day it once again ran for about 15 min and started poping in the exhaust like un burnt fuel was combusting in the manifolds, i rushed it home and shut it off and it hardly started once again, so i played with resistors, changed to my old coil again checked for spark from the coil, from the distributor and that was fine pulled a couple plugs and they were verry black and sooty (btw the car was starting to smoke black when it would idle low and i would touch the throttle to keep it running) i cleaned them and still no easy starting, has any one had this issue and solved it? i hope this is enough info.. im also running the silver perf. ignition box from chrysler and im running it on my 383.. thanks guys for any tips