Cig1, generally speaking you run less risk of damaging a BBC by making it grunt than you do spinning it to the hill. When in doubt, I would go with less revs than more if given the choice, if you are talking motors. No reason to beat the motor to death for no gain, only way to truly know is by testing. Every combo is different, too many variables.
I had a very similar outcome as jdnca1 while prop testing. Key is you need to test and take notes, becasue it is hard to remember all those figures when you are out on the water!!!! I agree with jdnca1, Daze and Tomcat. Regardless, have fun