there is 3 ways to fix this 1# is to knurl the piston with a pistons knurler.2# try another set of pistons set of forged pistons can take more piston to wall3#bore block out to the next size up. there is others ways as well custom pistons were any size can be made i have done this were we just bump up the pistons size by .002or more put a sleeves in the block or new block.send pistons out for skrit coatings