I didn't realize the gearing change was that extreme!
no wonder you were calling 47mpg's crappy!
I hit the mounts (actually everything) with my flap-wheel first, and then with my harbor freight(lol) spot - sandblaster in all the crevices before painting. good as new as far as I'm concerned...
{EDIT} : don't know why i can't get the pics to show, but the link is good if you want to follow it and see some of my "ghetto craftsmanship"!