An HEI is a bit over the top for an electrical DA such as myself. I'll check all the usual stuff. Then open my wallet and have the mobile mechanic repair it. Then work double OT to pay for it. Just cost me 238.00 for my FORD 4.6 it spit a plug out FORD wants 4,000 for a new engine or 2,000 for a head. They will not repair it so I had it towed to a shop. Fixed with something that looks like a heli-coil. Had it back the same day, NO more Ford's for us. At least the 235 running or not is all cast iron! Any other ideas pass them on and we thank you. Steve