Well at least thats what I think it is. The truck drives fine under light load but as soon as I give it more throttle the truck sputters and bucks, although it does gain speed. Ive noticed it to be the worst in 3rd and OD but I think this is based on load on the engine more than anything. SO far i have replaced dist cap, rotor, plugs(a/c delco), wires, ICM, Ignition Coil, engine temperature sensor. This seems to be a common problem. So hopefully someone can help me out. Ive tried just about everything.

I'd be checking fuel pressure during the misfire event. As you see random parts replacement rarely fixes the problem! Any engine codes stored or pending?

No codes were thrown. All those parts had a possibility to be the cause. starting from cheapest to most expensive. fuel pressure checks out 63psi
76 on the return line. and no quick leakdown.

Ok, you should be past the fuel issue. At this point a full scan is in order to look at fuel trims, misfire events and sensor inputs.