Yup. The converter was still full of fluid from when the trans was removed a few weeks ago. It was only pulled out to replace the seal. Having learned from breaking the front pump on a Ford C3 eons ago, I triple checked to make sure the converter is seated all the way in. Yes, it's bolted to the flex plate.

I do have another theory after flipping thru the FSM last night. There are two additional parts to the flex plate assembly: the adapter plate which goes on the outside of the flexplate, and the "crankshaft bush" which goes in between the crank flange and the flexplate. I don't know if it's possible to reverse the order of installation. It's hard to tell from the manual diagram. If so, I suspect it could possibly move the flexplate further away from the trans and not allow the converter to seat fully into the pump. If someone has a 3.0 with the flexplate still attached, maybe you can tell me which piece goes where or at least give me a measurement from the rear face of the block to the flexplate. It would certainly explain why BOTH transmissions exhibit the same behavior.