tranny swap question- T700 to T400)(TH375)?

[crossy]

I’m trying to help out an older gentleman who uses his 85 Chevy C10 for scrapping and recycling to supplement his income. He has 7 kids at home too! This 400 will be much better for him in the long run. He has very limited mechanical skills but has a friend who is going to help him cause I don’t have that kind of free time. I will verse him on the converter engagement issue and told after it is in and filled with fluid I could adjust whatever might need it.

Anyway I have one of those funky TH400 trannys that came out of an 86 C10, I didn’t remove it or I would have saved and marked all the supporting componets. Some people call these things TH375’s ,but it is a th400 with a small output. It appears, without measuring, that this 400 will bolt right in where his dead th700 is. I thought that was the reason GM finally did this was so that they can use the same driveshaft and crossmember to mount either tranny depending on options of the truck. Saying we want to put this in his truck, will it bolt right up to the existing crossmember by just moving it to different holes in the frame?? I have no rubber mount on the T400 so I assume it is different from the T700?? What did the T400 use for kickdown in the late 80’s?? was it the electric solenoid??. any useable info appreciated.