Help me figure out what TH400 my brother has

[josh86k10]

Let me start by appologizing for the uncertainty of the information that I have. I am trying to identify a transmission that belongs to my brother (who is in Homestead, FL) which is sitting at my father's house (in Estill Springs, TN), all from my living room (which is in Knoxville, TN). My brother bought it for a TH400/203/Ford 205 doubler set-up, but I fear that it is a 2wd tranny. He bought it without consulting me. All information that I do have is from asking my dad to go out to the barn (where cell phones don't reach) and take measurements of what I tell him to measure by memory.

Here's what I have:

• Plate on side of Tranny: 305
  
  85 F M 25378
• There are 4 holes (2 on each side) for the inspection cover which appear to be tapped 1/4-20
• The output shaft sticks out 5" from the seal, 1.75" past the back of the tranny housing, with 1.5" of splines
• There appears to be a hole in the end of the shaft (but he couldn't remember if it was threaded or just a centering mark for a lathe).
• There is no cone on the back (of course I believe they are removable).
• Of course, the shaft is 32 spline (just like most of the eleventy-billion output shafts GM used in TH400's over the years)
• There is no "K" or "HD" on the bellhousing

What the hell did this thing come out of?

 

[4X4HIGH]

It is a 2WD case and sounds like it either came from an early 2WD truck or vette that used the bolt on Yoke with a slider in the driveshaft.

 

[77fixer]

The shortest 2wd tailshaft sticks out 4.5" from the back flange of the transmission case. Since you said it's about 1.75", I would say it had a 208 attached to it. You could also have him look for the speedo gear. There are two helical gears on a 2wd, one for the governor and one for the speedo.
None of that really matters since he needs to change the output shaft anyways. The one he has is not correct. The case it is in is a matter of preference. The speedo assembly can be replaced by a freeze plug.

 

[thatK30guy]

A 6 bolt dust cover K case doesn't always have "K" or "HD" on it. I've seen the number "28" on one before.