Hey Pat,
That situation sound kind of familiar?
Listen to Mr. McCarthy, he knows more about BBC's then anyone I've worked with before. He just went thru my 509 and "fixed" it. I purchased the engine assembled and it had the exact same heads you have, about 11:1 CR a solid roller cam and a few issues he found after he opened up the motor.
I sold all of the top end stuff and Pat built me a motor that will run on the street and be fun to drive. If that is what you want, give him a listen. Are you in Muskegon? Not that far from Kawkawlin...
Mark