Off to the tranny shop!

Did you verify it is the front pump seal? If so it could be the pressure is too high. I'd say put it up on a rack and test the pressure. If the pressure is ok it's something mechanical. Either the snout wasn't repaired correctly, the seal got nicked when installing the converter or there's a problem with the front pump bushing. It sucks but the only way to know for sure is to yank it back out, again.