ok, crackedback got he # right, it's 3418623 which in my book says RH 91-73 A, B, E 340.
The other is not listed in my book but 3751083 is the closest # and it fits LH 73-74 B, C, E 340 and 360. These two were a matched set on an engine I tore down years ago and the cast date is really close on...