I'm not sure Chrysler ever made a lockup 727 for a slant 6, did they? I tell you the truth, I'm not sure I really want to investigate it any further. I'm pretty happy with this gear change. It's growing on me. It's nowhere near as bad as I thought. Maybe if something falls in my lap with an OD.....or if I can adapt this T5 pretty reasonably......now that would be cool. Key word "reasonably". lol