I have a 1993 GMC C3500 7.4L manual trans with running issues. When the engine is cold the truck has a rough idle and revs up and down. When the truck has warmed up it idles fine just a little low around 350 RPM. When in the driveway it revs to redline fine with no issue. Once the trans is put into gear, the engine will idle fine but as RPMs approach 1000 the engine starts to stumble, loose power, and begins to pop through the exhaust.
Parts I have replaced:
distributor ( came with new cap, rotor, and ICM)
fuel pump strainer