I'm boring to 75mm on 5e, been looking around for blocks cracking and found nothing so far, heard a lot of people using 75mm vitara pistons so should be ok Best this is to get the block ultrasounded there a tool that measures the block walls properly Other thing is most places stock 75mm pistons too so can't be prone There is not much cc gain tho, mainly done if a 74.5 has scored the bore Is there a reason for the rebore?