I am curious, what size brake lines are you running with your manual brake set up? My buddy has a Demon 340 with aftermarket front disk and rear 10.5 inch factory drum brakes. You really have to stand on the pedal to get it to stop in a foot ball field distance.
I do not know what size master cylinder or calipers or wheel cylinders he has on it. I do know from just looking at it, it is a later model Dakota type MC.
Thanks Jerry