what size is your piston now? dont bore it all the way out if you dont need to....and if you have to, i would say screw it and buy a BB sleeve and top end.....little more coin, more along the lines of what seems to be popular mod......
if your cylinder sleeve is in good condition...you can just hone it...if you have bad scarring or knicks...you'll need a bore...how big? depends on the flaws.....