So should I go about .010 or .015 over, we run alot of nos on this engine. I dont want to screw with this combo much, it has won 6 races this year already and 2nd or 3rd in the rest. I put my spare set of pistons in 3 weeks ago and need to order another set, I want to get them bigger so I can bore it next time. All the cylinders look great except #4 has some minor scarring from a burnt piston. I honed it out but I just aint happy with it. It takes about 6 weeks to get the pistons from Venolia and I want to go ahead and get them ordered so I can plan this rebuild during a time that we dont have any big races scheduled.