I just installed a power up kit from Hetrick, pipe, carb, cdi etc.. and it's running great but seems to maybe me geared to low. I'm running the stock 15 front 28 rear on a 520 chain and I'm running 16 snowhogs. It will mainly be used on flat tracks.

 

I think you arent geared too low. The B-52 or porting on your cyl and some clutching changes will get a lot more mph out of the bike.