This unit if it,s the cast iron unit is used on 65&66 10.5 flywheels for 361-383- 413- 426 engines on B&C cars,mrmopartech
if it,s a alley unit,it,s a 65 B unit for 426.
According to Brewer's website this is the Bell to shoehorn a BB into an A-body. 2468370 is for a C-body. Both Bell's have a 4.354 retainer opening. Both are cast iron.