I got called to help a friend diagnose the missfire in his freshly rebuilt 96 4.3 GMC. I carried my buddies snap on solice to help with the checkout. There was a new napa cap and rotor as well as wires installed on the motor, the cam was change to a competition cams model that was sold as basically stock. The solice showed missfires on #4 and 6 cylinders so we changed back to the old cap this missfire went away. When we tried to set the distributor phase or cam phase whatever its called, the solice showed 29degrees, we thought the distributor was turned as far as it would go so we changed the rotor one tooth in the cam and checked it again. This time we got -31 degrees. The problem is that the distributor will not turn to correct the phasing, the hold down clamp for the distributor is made and installed on the distributor such that it allows no rotation of the distributor as long as the bolt is installed. Any body fought this battle before? The truck runs but has no power, I've never seen this before. Any suggestions appreciated. Thanks
