need some sb help with hp ratings, /6 converter and cam

I'm building up a 318 magnum, I used Mr gaskets .028 head gaskets and with the magnum heads and .050 in the hole puts me at 9.5-1. I'm down to selecting the cam and I'm using a /6 converter out of a 70 duster. The converter is natural balanced and the 318 is internal so it all bolts to better with no problems. But in order to get a better ideal of a can, I need to figure what the stall is going to be. I understand converters stall at different speeds behind different motors. Hears the motor specs so far.
318 magnum from a truck
9.5-1 cr
Stock every thing els any one have any ideals at the HP #s and help with cam selection? I want a high rpm screamer. And yes I know springs are a must thanks guys