It has the rectangular cover, and it is not a T86 toploader. Just the run of the mill stuff. i have some good photos here:
https://www.hotrodreverend.com/in-pr...g/transmission
What gets me in all of this is that I had everything back together and the thing did really well for a few months. Now this. But, to be frank I only did a visual inspection, never checked the brass syncrhos against the cone, never looked at end play, and all the rest. I did replace the countershaft (not the gears, they were good) and the needle bearings. The transmission, I was told, was from a car with no issues... presumably a 55 Mercury but I have no way of knowing. The casing end on the tailshaft is certainly different.
I did talk with Mac Vanpelt today. I am looking at $1500 or so for a rebuild.
Ouch.
I feel confident I can do this myself, just don't want to pull it in and out several times and miss something. I already had it out a second time to repair a leak that wouldn't stop, so we are back to yankin it out again I am sure.