From what I understood it was a HD version of the same joint venture 10 speed being used in the GM and Ford HD or Super duty trucks .I knew about paying for the name badge. Didn't realize same transmission in 2500 HD / Super Duty too. I was aware of 1500 / F-150 sharing.
Last rumors' on Allison was they were seeking to partner with RAM since GM was no longer using their trans, and RAM was looking at what both ZF and Allison had to offer for the RAM HD line.
RAM being the only HD left with a 6 speed. I would expect RAM to get a new 8,9,or 10 speed trans real soon.