The Commando motor (235HP) got it's increase in power from domed high compression pistons, single plane 4 barrel intake and AFB carb, and I'd have to double check the specs in the FSM, but think a slightly hotter cam and the low restriction exhaust. Overboring should help a little on a power increase; but the pistons, 4 barrel and a thoughtfully selected cam would do the most good.
