961TonDually
Newbie
I have a 1996 7.4 Gen 6 that I rebuilt and added a 454/502 HO cam. I rewired it and I'm no longer using the ECM. The spark is no coming from an HEI. The fuel is coming fom a 750 Holley. I'm running the stock Gen 6 heads that had some work done. I'm looking for different spark plugs the are the same length and seat as the original but with a 40 thousand gap. GM calls for Delco MR43T in the 454HO engine but the seat is shallower and will not fit as deep into the head. I tried going to the part houses but they don't have the knowledge as the old days before computers. If it's not a stock part for that model, year and engine in their computers they have no idea what to look for. I'm using Delco Rapid Fire #8 with a 35 thousand gap at the moment but feel there may me a better plug to try. Anyone have suggestions?