Just got back from the trans shop and they confirmed that the torque converter that was originally given to me was a 30-spline unit and not the correct 27-spline that it should have been.
I inspected the teeth on the stator support and the input shaft and everything still looked new, no damage. They got the correct converter and pushed it on. This one works the way it should.
We'll be putting the trans back in the car this evening and I'll be driving it around all dirty as hell shortly after completion.
Wow, instead of paying a shop to screw up my trans, I decided to do the job myself and I ended up getting to do it twice. Bonus!
Here come the 11's baby!