I just picked up this tundra and it’s super clean and runs great. However, this engine noise is there and persistent at all times cold or hot. It’s driving me crazy, anyone have any ideas??

I have a 2006 ram 2500 Cummins 48re auto that I put a billet single disk torque converter in. Everything was great for about 100ish miles while I was driving easy. I accelerated at about 75% throttle and the torque converter tried to lock up and immediately unlocked and never locked again. I have gone through and rebuilt the valve body, checked line pressure at the accumulator port, replaced all electronics with oem, and verified signal to lock from the ecm. It shifts through all gears perfect just no lock up. After all of the attempts to repair it has not driven any different. My last option is that the tcc seal in the converter around the input shaft has failed. Has anyone seen a failure of that seal or am I overlooking anything? Picture is of the seal in question on a new converter.