[Richard]

Have a 2000 c2500 work truck with 240,000 miles (400 chassis) was running badly. Did the spider upgrade and a full tune up. Ran great. About 6 months later was missing again. Pulled the manifold again and did the intake gaskets again thinking I screwed up. Still ran like crap. Turns out the "premium" distributor cap from Oreilly's was bad. Crossfire inside the cap. Replaced under warranty. Unfortunately it has been replaced again. I did not bother ordering the Delco because I suspect it is probably made at the same place.