Personally, I think anyone who wants to hack a Sportster and ride it a lot has to be a bit mad... Counting the XR, I have three hacks running. The others are GL1200 and KLR. The XR seems to always need something, while the GL and the KLR just... run and run and run.
While the XR took the most work to build, I really enjoy riding it more than the other rigs. Cracking the throttle at almost anything above idle and feeling the hack get all twitchy with accelloration is addicting. And sliding around dirt road corners with the car tire is almost funner than sex...
Yours is rubber mounted, yes? Would appreciate it if you could keep me/us posted regarding how that works out. I had some wired driveline noises, and replaced swingarm bearings (with stock) and replaced the rear rubber mounts with polypropylene solid units. Unfortunately, I was in a hurry prepping for a trip and did both at the same time. So I don't know which item solved it. But the vibration due to the solid rear mounts is a deal breaker. With the rear solid, the front mount moves so much the engine is a blur; and the wife can't keep her feet on the pegs! I'm switching back to a new set of stock rubbers this weekend. Would love to hear how yours works out. I would also strongly suggest to keep a watchful eye on the hack mounting bolts... Seems I have to cinch mine up every 1000 miles or so.
Just because you're not paranoid doesn't mean they aren't out to get you...