all the engine builders i talk to won't build an engine with KB pistons unless they gap the top rings @ .030+ (4"bore). i, of course found out the hard way.
Pretty much. Only if you build a 9.5 comp or sub 170lb dynamic/cranking motor can you run .028 or .029 and survive.
I'll be running .034 or .035 on my next stroker incarnation.