I got my 6.5 turbo diesel engine running on a stand, the NV4500 is off being rebuilt and converted to 4x4. My trans shop is using an advance adapters kit to take the NV4500 to a round pattern NP205 which they are also building for me. The transmission will be more expensive than the engine swap
6.5 is a 1992 mechanical injection motor. I replaced gaskets, water pump, timing chain, harmonic balancer and pulley. Gave it a rattle can "rebuild" in the process.
YouTube vid of motor running on the stand.
https://youtu.be/417k1ZJRQ4A