summit cam selection

I ran a Hughes 218/228 cam with .528 lift in a 318 Magnum, it had tons of torque and power. Of course the magnum heads flow better, but it should work fine for you. it was mild enough at idle so that you knew it had a cam, but not too much lope, good vacuum, real good response. My only worry would be those 273 manifolds, might be little restictive. I think since you have the 4 speed, I would go with the bigger cam, which really isn't that big.