They did until pretty recently bc I was looking at it as well, might want to give them a call. I was thinking about it for my 70 RR, I have a 23 spline trans (out of a 69 or 70 383 RR) but I am putting a 66 426 into this car. After much research I decided it wasn't worth it and will stick with the 23 spline. What makes a Hemi trans a Hemi trans is more than just the input shaft spline count and size, it has a variety of other differences which cannot be duplicated. At the end of the day, I am not racing my car so I think my trans will be fine.
