1993 GMC Sierra 1500 350 Engine!!! Timing!!
 

Problem: Trying to set timing! Timing was already off. So I asked a friend to walk me through the steps and I am still having problems. Ok so first off I set the timing mark thats on the crank to the first mark on the clip that conects to the timing chain cover. So im guessing thats negative 1 degree. then I started it and steped on the gas to drive it and it starts to bog down. I parked it and I see that it advanced timing alot???? Is there a timing advancer on these trucks? Like a vacum hose or chip to pull out and set the timing then reconect it?

Ther is a wire you have to disconect to set the base timing, im not sure which one though, It will specify in a manual if you have one.