Identifying Th-400 tailshaft

[tomkr101]

I want to replace a shot 700r4 in '83 Suburban (350ci) with a Turbo 400.

One TH-400 is too short, and one would be too long, (which is an easy fix) The tailshafts are designated models "C" and "D". (from what I can tell)

Does anyone know if you can tell from the ID number which is which? I'm having trouble getting an accurate measurement of total length without running all over the country and doing it myself.

Thanks for the help!

Tom

[tomkr101]

OK. New question, situation changed. I found a guy with 2 turbo 400's, both different lengths, so the longer one shuold work, whatever it is.

Will an '87 tranny fit my '83 with the 350?

Thanks again