Hey guys.
So I have a 1988 C1500 chevy and I have been having trouble with it. I just replaced a bunch of metal and dropped the *** out of it and as soon as I pushed it out of the garage, it started dying on me. It will start with a jump, run or awhile, then bog down and quit, and not beable to start again without another jump. I have tested the battery and alternator several times and they both test out good, so im at a loss. I have looked everywhere for a short or bad ground and have failed to find anything. Is there any test I can do to narrow down the search? The engine is still the same TBI settup, except with out the factory emission system, replaced by headers. This hasnt been a problem for over 2 years, getting rid of the air pump and such, so I doubt that could be the source of my trouble. Any advice of where to even start looking for the problem would be greatly appreciated. Thanks  

when you dropped it did you relocate any of the ground wires from the engine to the chassis or body?

did you relocate or remove any of the emissions/fuel system from near the fuel tank?  

The only thing I even touched while lowering it would be the ground from the chassis to the bed, which runs with one of the 8 bolts that connect the bed to the frame. I have checked this ground several times, and cleaned the connection well. Do you know of any other chassis/body grounds on the 88 c1500?