Buttman thanks for the reply. I didn't mention that I have the SE 6200 ignition. The Mikuni is a concern of mine as well. I think it is running a little rich. There is definately more throttle response with it and I hope I can jet this thing down. I think these thunderheaders might be the weak link in this. I eventually will go to 98" and head work (in the fall) so in the meantime I think I will dyno the bike once I get the cams in.
Ditch the 45 for a 42, might want the mileage kit from Mikuni cause even the 42 is too rich from the factory, and ditch the Thunderheader, which is really a 2 into 1 drag pipe. Your 4 degree advance for the 37 sounds good to me.