I have original documentation showing an AD NAPCO from the rear with a swivel frame. It is a NAPCO News pamphlet, which was a publication of the company. What year is your running gear from? The swivel frame was meant to take full advantage of the 4x4, and allow maximum travel over really rough terrain... join my forum if you'd like.
www.napcpowrpak.com click on the globe and join up.
