Joe,
Baltimore passenger car. The bearing retainer indicates it was used with the 553 aluminum bellhousing which was ONLY used in '63 on 409 cars. The trans could be used on SB cars by simply changing the retainer to the smaller diameter one to fit the 421 bell. The bolt circle and the front bearing itself are the same. It's a 2:20 close ratio.
I hope this helps.
Verne
I can also add that since the yoke is pushed in all the way, that means that the main shaft is not twisted. Unusual for a 409 car!