Not to hijack the thread, a TH375 is a TH400 transmission that has a TH350 type tailshaft(uses the TH350 size tailshaft).
I think we should be ok on the hijack situation Don,afaik Dave (Homer) has the info he needs and the thread title does ask for TH350 education.

I assume then that the TH375 was just a packaging excercise in order to get it to fit a particular vehicle?