My truck is misfiring..help!

[ivorton74]

I'm getting pissed off now. my trucks been running weird for awhile now and im tryn to figure it out. She's misfiring, hesistating, idles erratically and now it even stalls out on me while driving. I changed plugs, points,condenser,fuel filter, fixed the vacuum leak on my carb, checked my coil, adjusted the mixture on my carb and checked the condition of my plug wires. I know that the vacuum advance control on the distributor dont work and my uncle tells me that could be the problem. I'm starting to think that its my fuel pump but im just guessing. It would idle smoothly one minute and erratic the next. anyone know what it could be?? Im getting frustrated!!