That's the thing ...my machinist wants the pistons before he starts boring.... So I'm starting from the bottom up and will match the cam....I was going to use the 516's with a light port stock but I'll do the bigger exhaust valve if you guys think it make a diff. .....so would this piston be what I'm looking for? I think it is as the 516 is like 78cc so i should be over 9.1 or better on compression ....
Do I just do the hardened seat on the exhaust valve or do you always do both? Thanks