1984 Chevy Van Engine sputtering/misfiring at idle and whil

Engine Performance problem
1984 Chevy Van V8 Two Wheel Drive Automatic 145k miles

a Week ago my engine would crank but no turnover, I refurbished the carb in the meantime while I figured out the problem and when I put it back in, it started up but ran rough and would not stay idle. Recently replaced spark plugs and fuel filter and now it will idle but gives my van the shakes. I went for a drive and it cut out about twice at a stop, wouldnt push above 35mph (I didnt want to work it over too much) without misfiring and hesitating and theres momentary 'pops' like popcorn, being fired out the exaust at idle. My van is a slight project so it probly has carbon build up and may need a fuel system restore so could it be the fuel pump? And would mine be electric or mechanical on my 1984 chevy G20 sportvan 5.0 OHV? And the location of it.