the bottom end is still stock. this motor dumped its crank 8,000 miles ago, and the case was split, and a new crank installed, so i left it alone, and went with a 95" kit from T-Man Performance. this guy WAS an Amsoil user. hmmmmm, i only know of three harleys that dropped their crank. not race bikes, one bone stocker, and two that were hopped up a bit. what did they have in common??? Amsoil...... i use Torko. never had an issue. to each their own...