The diesel tranny is identical internally except for a spring on the second gear accumulator, the 4.3 front-band (second gear) lever vesus the SRT-10 5.0 front-band lever, the front clutch disk count (Diesel 6, SRT-10 has 5), and the detent/TV valve linkage (SRT-10 has a cable, the Diesel has an electronic module). The electronic module is used because the Diesel motor behaves so vastly differently depending on whether or not the turbo boost has come on or not for a given throttle amount, so it takes a computer to determine how far the TV valve should be pulled.
I'm not sure if the bell housings are the same or not, however...