I may have crowed a little too soon. I drove the truck to work today. The first few miles it was great. Then it started to backfire through the carburetor. The engine will rev up, but it lacks power. It sounds like a one-lung engine next to the 6. I know it needs a new set of plugs, any other ideas?
A stuck Valve could do this...
Check your Valve Clearances.
Timing being far too advanced, or wrong firing Order, could do it also.
