yea, you can get .090 over pistons.. i hope you didn't pay that much for those cylinders.. you can only go .100 over on them. so you have one more bore left if you are lucky... lets say you get it together with the .090 over pistons and you have a bad failure, lean it out, dirt gets in, or whatever, and the cylinders get grooved real bad, they will still have grooves in them even after boring them to .100 over... if you gotem cheap don't worry about it and rock on..!!!