That would be the spec for an R100 piston. I must not be getting a good measurement. Will have them checked out.
There you go ... an R100 set. Yeah, I'd get those calipers checked out ... or better yet, buy a new set ... they can be pretty cheap these days. I actually have my grandfathers set ... it's a 'slide rule' type ... I can get 0.001 accuracy (with enough practice
Those the iron bores? Might want to think about a set of Nikasil's ... Should be plug and play, and you'll never have this probelm again.