Those are what you need, that is different, to upgrade to the 18 spline input shaft. Original mainshaft was hardened, but an A body mainshaft is plenty stout. As is the standard A833. I was just listing what one would have to change if they wanted to upgrade to the 18 spline input shaft trans. I would run what I had, unless I found a deal on an 18 spline trans. Or I wanted a Passon Performance Hemi O/D.
