there's a cutoff year ~65 or 66 on A bodies & the early ones had a much larger tapered outside round face that the key goes into as opposed to the later flat round lock cyl faces, barrel dia might even be larger on the earlier ones as I'm thinking you are referring to.
Year One has them listed as '66 - '74 B Body
Autozone has them listed as '66 - mid '80s
Classic Industries has them listed at '66 - '76 A&B body
I thought my paint may be too thick around the hole. I had this problem with the trunk lock hole. The paint is pretty thin around the edges on the door holes. I'm really at a loss.
