Hey guys bought a b18c1 block that was bored. The guy said it was bored 10 over. I know that B18C1 pistons are 81.0mm/3.189" so is that .10mm over or .010" over? I have arias pistons that came with the block that are slightly scarred (also 10 over) so i want to replace them with the right bore but dont know what to get. HELP

 

.010" is about .25mm,1.0mm is about .040",.10mm is only about .004".Measure the bore,it is probably close to 3.199".
Glenn