Bet you that thing does run crisp on the street. Considering it has a dual plane manifold and assuming the divider is not cut down, each cylinder only sees 375 cfm. A big prepared thermoquad would be an excellent choice carburetor. Those manifolds have to go, fenderwell headers if you can find a pair.
i'd actually go the other way and keep the carb small-ish... 4150 with downleg boosters, mechanical 2ndary if i wanted to be shenanigans, and some tri-y headers 1 5/8" primaries.
i think that would have all the things i'd be looking for: kickass throttle response, enough carb to pull the motor to peak power, absolute gobs of midrange torque without sacrificing anything down low or top end.
that's a basically: stick any gear in this and watch it melt the tires at will.