Orrrr swap in the DT466. That is/was what was commonly found in these and ideally you can then swap it over to stick shift for the extra gearing. Most were 6&7 speed trans but some came 5 speed with the split shift for 10 gears. If you can find one that is pre-emissions you dont need the DEF fluid. I recall up until around 1996-7 they still used a mechanical fuel pump instead of electronic fuel injection & emissions.
School buses are a great inexpensive and well maintained source for motors as well but most of those are auto trans.
School buses are a great inexpensive and well maintained source for motors as well but most of those are auto trans.