have a Vortec 350 replace oxygen sensor spark plug wires still have a miss

"Not fuel injected" are you sure? The vortec 350 has a couple problem areas that cause this: vacuum leaks, distributor cap and rotor, sometimes the Spider injector. Unless you have done some modification your truck is fuel injected.

I'm going to check those things out it's not fuel injected how do I check for the vacuum leak

I was trying to say it in a polite way but your not getting it. Your truck is fuel injected. If it's really not fuel injected then try rebuilding the carburator

there is a spider injector under the intake manifold you can't visibly see.