I go to Crago Racing in Van Nuys. He's (Jeff) been my mechanic for 15 years. He knows how I ride and has helped me set up the bike for the way I ride. He's extremely knowledgeable. His shop has a dyno, and he has maps too. He does LOTS of Busas and is doing the nitrous/turbo Busa engines for the cart cars at Pahrump.
That being said, all I ever recommend is, call him, talk to him, if you like what you hear and the prices...cool...if not, that's cool too. 818-780-9144 tell him Owen sent you.