I think my 727 is fried. Now I'm at a crossroads...
Hang on man, you may just have aerated the fluid with TOO MUCH oil in it.
If the fluid is not blackened and stinky;
I would check the calibration on the dipstick, run a deep pan with a filter extension, and drop the oil level until it is well below the sunshell. Then roadtest it.
Oh yeah, make sure the cooler lines are not kinked, lol.
Obviously if the fluid is dark and stinky, I would drop it out first. If it comes back slipping again, well, you tried.
The talk about building the engine differently for a manual trans is more than just talk.... But on a low-performance effort is not a big deal.