the balancer is brand new from jegs, not stock. its a professional products brand balancer. looked to be the same width as what came of the car.
http://www.jegs.com/i/Professional+Products/428/80012/10002/-1
i was talking more the pulley of the PS pump being different between small and big block. seems kinda silly they would be different style to run the same pump on either block. doesn't seem cost effective for dodge to do that to me. but idk.