hello, was inspecting a 903cc engine over before i put it into car, and noticed when measured bore size which should be 65mm varied from 64.5 64.7 for the life of me that does not compute, pistons are marked B-2 does that mean anything to anyone? took top compression ring of took measurements at top of bore and bottom and results indicate worn bores, just puzzled at bore size, does fiat always under bore , kind regards dave
