Converter stuck in cranksaft!

I am done for the night. I installed the tranny 3 times tonight, with no luck.
on the nub of the converter itself it seems to have a ring around it, possibly a "cap" of some sort, that is what it is getting stuck on (I think?) is that ring, it sticks up a 1/16 of an inch higher or so. I would just sand it more, but suppose it is a cap... that could be bad.

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