Try a comp cams 280 or 292 magnum.With your comp ratio and intake this will be a good match for 5k-5500rpm.Get the proper springs too.I ran this similar set up in my 71 camaro bbc 396 car ran 12.20s@108.I would consider this a reliable set up too.This was my only exp with bbcs as my current boat motor is an 11-1 bbf 429 with similar cam specs too but i am running a b+ impeller to get the motor to the upper rpm range.head porting is on the way.