Yeah I'm just going to do the whole top end the next size up. From what I read, the '29L' crank is the stock yamaha crank after all, so the guy I bought it from who said it's a 390 stroker, either didn't know what crank he put in there, or was just fullof it... But either way, this crank gets the 513 pistons (or whichever brand non stroker pisotns I choose)? I'll need to find a shop to bore them out. The only one I've found so far quoted me $320 for the pair. Sounds about twice as much as it should be, right?