I’m working on a 340 with a 360 scat crank in it right now. My 894 heads cc were 72 with a .052 gasket and a -.008 deck with the KB 107 hyper junk pistons. It blew the top of the piston off above the ring about 2” long. I’ll post pictures from my phone later. It was about 9.25 CR. The motor showed no signs of detonating and the ring gap was .036 with about .004 piston to wall clearance. I’ve got another post about it but have not updated it with my findings yet. The Hughes engine site list most small block combustion chambers at 63? Mine were not. Maybe they are working off magnum heads figures. I get blasted every time I comment on these pistons being junk with “ it was not built with the correct clearances” guys, but I refuse to use them on a build. Incidentally, I called THE leading Mopar guru in the world and he’s shares my opinion on them as well. Without mentioning his name, he referred to KB hyper junk pistons as “ f***ing junk made out of melted down beer cans” . So at least I stand in good company.