What's broke?

That is my sense of the event, yes. There were several things happening at the same time. I could have misread events, but I don't think so.

I was concerned from the beginning with how the whole noise/mess (what started this thread) came about. The 'feel' at the shifter didn't seem to quite fit my early diagnosis (transmission front bearing failure). Replacement of the transmission did smooth out anything that seemed to maybe be coming FROM the transmission...but the first-noticed 'not quite right' input was still there and identical to my first 'What's this?' impression with the original trans.

A shake/shudder/shiver on the input of the trans would certainly translate through the trans. No rocket science there, but the vibration was 'off' enough to be misleading. To me, anyway.

I found out long ago that ignition coils can do strange things. With an MSD-5C box and an Accel Super Coil (recommended by MSD to run with that box) I experienced several 'vapor lock' seeming failures. I never did figure it out at the time that problem cropped up. It didn't happen on race-days, it didn't take an abnormally hot engine or an unusually stressed engine (mountain pass climbing). The problem would just 'happen'. The engine would respond to more fuel (dump the accelerator pumps into the engine), but it would not 'cruise' for diddle...missing/stumbling something awful. Bad enough to fumble off to the side of the road and turn it off. The ONLY thing I found that effected the problem was to change all the plugs. YEARS later, it was Mattax IIRC that said an overheated coil could cause what seemed to be a vapor lock issue. By then my MSD box had suffered a complete failure so I wasn't using it. Still used the Accel 140001 though. Never had the problem again after offing the -5C box.

A btw...but with that MSD box I had constant problems with detonation at 'cylinder fill' time of around 3200rpm. Ate a piston with it eventually even with timing turned down such that I did not HEAR any pinging. After the complete failure of the MSD box (engine quit running in the driveway one day) and putting in a Chrysler style spark box, the detonation problem disappeared. Everyone I asked at the time said, 'That's not possible,' including MSD. Fine...except...I was here and I saw/heard it happen.

I'm sayin'....coils/ignition can do strange things.

**edit**
May be unclear what I'm saying. Hey! It's clear to me!! The best term I can think of that would explain how an ignition problem could cause what seemed to be noise coming of the transmission is 'gear roll-over' noise. That term is commonly used in diesel applications, probably due to the torque involved in a diesel. The engine literally slaps the transmission silly with input pulses. Gear roll-over noise is usually lessened with a change to a higher viscosity lubricant in the transmission. That was the case in this case.

Who all here remembers the M-22? ;)