Dodgem & Todd, I did switch to Champion C59CX plug. This is the same plug my machinist runs in his street stocker 11:1 compression. He was the one that suggested these. They fuel fouled just like all the others (NGK type). I'm running a stock carter 6pak style pump. So, I'd say 5-6PSI on pressure. I'm going to go get some 110 octane and run directly out of my gas can, by-pass the tank altogether. I'll get back! Take care!! Jeff