904 vs. 727

hey ive got a question. Ive got a guy who will sell me a rebuilt (never re installed) 904 or 727 for $125.00.Same price for both.Im putting it a 72 dart with a soon to have slightly moded 318(carb,intake,maybe a cam),8 3/4 rear w/ 3:23 gears.
what is your suggestion?904 or 727? what i want is a muscle car.not a strip racer just one that can somke tires and race at a light.300-400hp maybe.