I don't think you wil have a problem with pump gas with that compression and cam setup you have. I am currently running 11.4:1 on a 377 with a smaller cam that you are talking about going to and don't have a knock problem. I was using iron heads and still didn't have a problem now have aluminum heads running timing at 36 degrees no problem. My quench is .045 with flattop pistons.
Where are you located, I see bayou for your location, I assume your located in Louisiana, I'm located in Gonzales.