At some point Ford took a medium duty 4 speed and made the 3rd gear postion into an O/D. I know this sounds strange. The trans can be identified by a bulge on the rear passenger side, where the case was enlarged to clear a larger gear. The 3/4 shift arm was reversed (pointed up instead of down). Compared to the original, moving the shifter handle in a standard H actually moved the gears as 1-2-4-3, since the modified 3rd was now an O/D. The one I had used a 3.27 or so 1st, and a .8 O/D.
I believe it came out of a Granada, and at the time they were referred to as a T&C transmission. Been 15 years, so my memory may be missing something. On a Y block bell, you had to turn the front bearing retainer down a little, and drill and tap two new bolt holes in the bell. They were a cheaper short term solution before the T-5 variants came out for higher torque ratings. I wouldn't do one today unless it was close to free.