your really close to me man im right about 5 mins north of camden lol yeah lots of places to ride around here theres accually a annual ride on good friday starting from 46 all the way up to oswego county it sure is a whole hell alotta fun haha
you take feeler gages and check the clearence bettween the rocker arm and the valve not sure about what the clearence is but you can probably google that
And for the top end rattle hows your cam chain if thats losse it will make some ratleing noises ive also heard of the wrist pin bearing making somenoises on some machines before too could be that who knows also posting a vid of the noise will also help diagnose your issue.
yeah that seems like a good way to do it but is there any more info to do the clutch cover oil cooling mod cause that seems like it would be a little less costly if done right but idk.