What is an easy way to tell if the distributor on my 93'GMC K1500 w/5.7 is worn or needs replacing. I have changed cap/rotor and module but the truck is still sluggish. Everything else on the truck is new including engine. I think my problem is in the ignition now. Thanks

Did you stick with A-C cap and rotor? Have you replaced plugs and wires? If you suspect the distributor, Rockauto.com has them from $100 to $200.

For dist wear check dist shaft side play.
How is the base timing?
Do you have good hot blue spark to and threw the cap and rotor?