swing arm bushings are shot in my 2001 scrambler so while i have the clutches out i'm going to change the belt to hpd also thinking about a roller clutch will i lose top end if i install also what degree helix should i use

 

Its strange that your swing arm bushings are shot already, are you religiously greasing them.

The roller wont affect your top end unless you mess up the clutching, when you order the roller hpd will ask you what you want to do with the bike and they will send you the correct parts, you should also get a clutch kit to work with the roller if you dont have one already.

I have been punishing my roller since they became available and so far it has been perfect.