How to ID a 440?

An RB engine (440) has the pad as shown circled in picture, while a B engine (383) does not have this pad. Its information is on a pad by the distributor. The pads information will give year and CID. example: "C 440" = 1967, "F 440" = 1970. There are other ways casting number etc, but the above is a quick way I use to determine.
The year A, B, C's started over in 65. So A=65, B-66, C-67 etc...