[b454rat]

It means it has the bigger tranny input shaft, not t-case. It's been a bit since I looked at this stuff, but IIRC, Cummins input is 1 1/4" where as others are 1 1/8". Also early GM 4500s weren't compatible with Cummins, but after 96 they were. Bells would bolt up as well as inputs.

I don't remember which one it was, but one of the 205 cases could be drilled and tapped to the other pattern. It's easy to tell if it can or not, it will have the machined flats, this is where the bolt holes would go....