Do you have to use the 4l80E? I'm not saying it's a bad transmission but the aftermarket avalible for the 47rh/re is impressive and designed to deal with the cummins. You can run the 47 behind a dodge 205 t-case and still use the axles from the chevy. If you used the 241 t-case out of the newer dodges you would have to change axles also.
Just a thought.
Bruce