Th350 to th400 swap. What do I need?

[Project86]

Finally was able to pick up a transmission for the low low to get my project under its own power and work out any electrical bugs/chassis issues.

Previous combo was a sbc 357/th350 short tail and stock driveshaft

I'll be swapping in a th400. It's definitely a short tail and it's a HD trans as well

I know the governor will have to be swapped out since it was behind a diesel motor.

What all will I need for the swap over? It already has a yoke in the tail housing.