My 2000 360 magnum has KB107 pistons in it. With those pistions, felpro 1008 head gaskets and 60cc trickflow heads. I am right at 11.1 compression. I race it on 93 pump gas. To the op you have to make sure you gap the rings like it says in the instructions. But my enginr has been together for 4 years now and has seen tons of 7000 rpm passes and I havent had any problems out of the pistions . It's been a while but I think the last time I looked the KB107 were around $320 a set on summits website. Also speedpro makes a set of pistions, but I don't remember what the part number for them is