This engine should make at least 800LARGE for power, I have a 461smallblock(that earlier in the post the guy from sasktoon had heard of a 462 in alberta, this is me, but its 461)pump gas 750 single carb NATURALLY ASPIRATED with indy heads light bobweight, basically the same parts as this buildup and mine made 741hp and 638torque. This engine is in a 68 barracuda street car with full interior,exhaust,etc...Best et is 9.52@142.88mph with a 1.39 sixty ft. on a 10"tire with leaf springs and cal tracs No trans brake.