For 1971 Mercury Cougars and Ford Mustangs with the 429CJ engine. This is a Pitts manufactured pulley and clutch assembly with a pulley diameter of 5-5/16", a clutch diameter of 5-5/16", and an overall thickness of 1-3/8 inches. Whew, say that 5 times fast!
Ford Part # D0VA-2981-A.