Yeah, it does ping a bit, if I really step on it. I don't think I've got a hole in my piston, as I say, it runs and all cylinders fire, I guess there would be even more irregularity if I had a blown Piston. I'm running with 91 octane fuel and a stock 350, stock cam, stock everything except for Edelbrock Performer Carb and Manifold. I guess I'll just give it another try, after all you learn with every mistake you make. But I damn well feel like I'm learning a lot these days ;-) Will changing the fuel make very much of a difference?