Over 40 years ago I spent many nights watching listening to Norm Fraser run 3 boring bars simultaneously many great stories and a boat load of fun.
Norm could bore anything including 750 Ducatis to 860cc long before the factory,
And a 700cc Pantah a year before the factory had the 600.
For Wisecos he had a very course cross hatch and run them in flat out after they were warm.
I sold both my boring bars 20 years ago, as a waste of space,
Lozza's idea of measuring a grown piston certainly is ideal but who would go to that trouble???