Well they were right, the rear of the transmission was NOT the same as the original one on my 1995 YJ! There was a two inch depressed seal on the replacement, whcih was not working with my existing converter. As recommended, I removed the rear of the original transmission case, and replaced the new case end with the original, and after bolting it all together, WOW! It all worked just fine.
I wanted to pass along the notes I used to replace this in case any one of you have a similar problem. Just remember, measure the rear end depth to the seal before any reassembly of a replacement transmission, or you too will suffer major oil issues.
1. Have Transmission in neutral.
2. This rear housing is only a shell, nothing complicated.
3. Remove shifter and transfer case.
4. Remove 2 large nuts that are located on each side at top where shifter was.
5. Inside remove 12mm bolt on shaft. At rear remove 10mm allen head bolt and slide shaft thru.
6. Shifter finger can now be wiggled out.
7. Next remove t40 bolt cap on pass side. (There will be a spring and ball with it.)
8. The only things remaining are the housing bolts.
9. It’s all actually very simple.
10. When you have remover the housing look at where the finger fit into the 3 linkages.
11. Make sure they're all in line, which is neutral.
12. You can practice on your old transmission first.