rockcitycafe
I make things.
the stock cb750 arm is about a foot long, it goes under the footpeg so the pivot is actually behind the heel. also, yes, those race bike rear drums may look stock on the outside but the internals are usually modified, such as the cam, I suppose an "easy" way to correct for some of the lack of force applied to the lever would be to turn the cam down in a lathe, but doing that would mean you'd have to make sure the shoes and drum were in perfect condition with very little space for the cam to take up, otherwise the cam could turn further than the ability of the shoes to push it back to neutral and you could wind up with a locked rear brake