Thanks for the info.
Yeah, the park ratchet looks like it could hold a ton easily.
However, with the trans sitting on the work bench it was pretty easy to jam the rear tripod with a socket and lock it up; so I went ahead and used that method.
All is good, assuming I fixed the shifting problem I tore it down to resolve, and I got all 17 possible leak points well sealed. Wish me luck!

DG