[David Pozzi]

You can pull the 3 converter bolts, push the converter rearward & run the engine to test it. Are you sure the bolts got tightened?

I had an engine with a shot thrust bearing. With the truck facing downhill it knocked. Facing uphill, it didn't. The front counterweight was smacking the block. You might pull & push the crank & check for end play. A rough finished thrust face on the crank could tear up the bearing, but I would suspect the flex plate more.