WOW !!!!! What a BIG difference.I've heard everything from,1st gear will be worthless to it rev's to high at 70 mph.Also,heard it's the best mod I have done.Just went on my first ride with the 3.37 gears,it is one of the best mods I have done.WOW!!! It fills like a different bike.It fills like I just picked up 20hp and 20fp TQ.WOW!!! Don't know what happened,but my noisy tw6 cams are now as quiet as my se211 cams where.And at 70mph it's only at 3200 rpm,I can't even tell the difference.Thanks to a visitor on this form,I traded my 3.15 gears for his 3.37 gears, saved me $500.And thanks to everyone on here for sharing there experience with guy's like me,who can build a house but need help spending there money on things there wife's can't understand!!!!