Timing Problem

[raychevy]

I posted this in the Engine board, and I dont think anyone knew for sure. This I think is a common 350 question. I hope someone can help me. I have a 77' Chevy c-10 350/350 turbo with 4 barrell. I had the timing checked and it was at 4 degrees. The engine sounds like it was running 4 to 500 rpm. It will slowly take off if the brake is released. What should the timing be set too ? And if mine is wrong could this make extra valve noise, and rob it of power ? Its strong now, but I think it isnt getting its total potential. I have a dwell and rpm test machine, but I cannot find the wire to clip the end on to make it work. The truck has electronic ignition. Anyone know what color wire im looking for ? Thanks in advance