where can i buy a 904 tail Shaft Seal for my 273

The mopar part number is 2464 854 for 65 A904 trans
The part number for a 60-64 A904 is 1942 401

OK, I located a source.
Home -Fatsco Transmission Parts
Their part number for the 65 A904 is SEL-3189Q Price is $12.00 plus shipping
Their part number for 60-64 A904 trans is SEL-3142Q Price $10.00 plus shipping