My truck started skipping real bad, and come to find out I had one plug with cracked pocelin, and a second with the porcelin gone. I put in some brand new plugs and now when I go WOT, and only WOT it has a real fast skipping feeling to it. The motor is turning hard but I am not hardley moving. Could this be a spark problem, or could it be in the tranny? I'm about to give up...

 

Not sure man, but it sounds like its the tranny to me. Did you check the transmission fluid?

Doubt if it's a problem with the differential or you probably wouldn't move at all.

If the engine is turning, that probably isn't the problem.