what are these pistons???

it's actually worse than you think..Those factory pistons+factory block machining= a true compression around 7.8:1..lowest I've calculated was 7.2:1, due to HUGE factory chambers in the heads too. The .509 cam is not designed for use under a true 10:1..There are much better cams that will run and make some power with the lower squeeze..Sorry I'm just reading this now..lol