360 rear main seal - Different PN for different years?

SCE 16905. I can post a picture of the package tomorrow. It says on it, 360 up till 91. Checking their site, it says 360 74-91. But I think they have their details mixed up and it's for a 273-340. They could have packaged it wrong, but I have no way to know.

Summit also shows a PN 16904, and I know there's something wrong on that one, they claim it fits both a 318 and a 360.

Summit wouldn't take it back, so free for the cost of a flat rate envelope to someone with something other than a 360 to try it on.