Check the coil and your fuel pressure. If it is a high speed sputter then you are most likely dropping spark or fuel pressure under load. Replace your fuel filter too. You didn't put those "lovely" cheapy Exacto wires on it from Advance Auto or Autozone, did you? Don't run number 5 and number 7 togather or zip tie them together either..especially if you are running the cheap wires.
A forum community dedicated to all General Motors truck owners and enthusiasts. Come join the discussion about performance, lift kits, wheels, tires, modifications, troubleshooting, maintenance, and more!