Are you running a fuel filter? If so id check to make sure its not clogged. I would upgrade your fuel pump, wouldnt want to lean that motor our so your better off with a good 110-140gph pump. Cant go wrong with the HEI, just transfer the wires from one cap to the other, make a mark on the intake were the rotor is and the base of the distributor is so you'll be close and drop it in. Id DEFINATELY check the timing regardless, should have around 32-36 deg total to start.