I was wondering if 1 motor makes 300whp on stock sleeves with a stock bore. And another makes 300whp on stock sleeves bored .020 over would the bored sleeves be a lot more prone to cracking? I know not all conditions can be equal, but a generalization as to if it would be safe(so to speak ) With a good tune I'm thinking it would be ok. I haven't really heard of a lot of people running setups that are bored on stock sleeves. Think I'm going to try it anyway. It's either .010 over with srps or .020 over with CP's. I'm going with the CP's. Anybody else running .020 over on stock sleeves with moderate power levels? Thanks. Less boost would be needed to achieve the power level, but it's also less sleeve... The block is posted btw.

 

I think you should be fine with that amount of overbore so long as you don't break any of the cardinal rules of engine longevity: detonation, lean a/f mixture, etc.