Need A833 advice

Jeez - a lot of activity here!
Yes, I centered the bellhousing. It's definitely within tolerance.
Yes, the bearings are correct, and are correctly in place, and the correct size. (A 'thicker' bearing would not fit, and the snap ring fits snugly, as it should.)
I assembled this transmission by myself, from my old A-body transmission, an E-body with the Passon gearset, and a new retainer (from Passon) that allows for the larger snout.
Note that this problem arose while Jamie was at the Mopar Nats, so he was initially unreachable. I did call and leave a message; he returned my call yesterday morning. He let me know that there was a batch of gears that were on the snug side, and that he'd seen this before. He says it will work itself out, and recommended that I reassemble/lube it, and run it in reverse (with the wheels up) for a while to help the bits wear in.