318 pistons

The problem with using a friends deck clearance measurement is it might be different from yours, that said I ran the numbers for those pistons with a different calculator. Assuming a 9.6" blueprint deck height, and indexed crank, etc, those pistons should be .077" in the hole. With a 64cc chamber, .040"x4.14" gasket, and the 0cc flat top, I calculated 8.48:1. It'll more than likely be a little less than that unless the decks are cut down below blueprint height. There's nothing wrong with those parts selection to save some cash, but I would definitely recommend you degree your cam and maybe even advance it a couple degrees to keep some of your cylinder pressure.

As long as you're not expecting it to be an 11 sec terror, I think you'll be happy with it.

Just my .02...