I'm looking at going to a bigger bore for my '99 400 rebuild. The original cylinder appears to be in pretty good shape, the bike has roughly 8500 miles which leads me to believe "it's due". Anyone have any personal experience with the following? http://www.maxpower-engines.com/big-bore-kits/yz417f.htm http://www.rageperformance.com/big_bore_kits.htm http://kustom-kraft.com/YAMAHAKITS.html Others I should consider? Thanks in advance for your input.