318 I’d numbers

Nothing online is real clear on the old poly motors. I have a 1966 Fury iii the engine says 2468230 and I also found B318 2 7.

I picked up a used motor from a estate sale it says 2468230 B318 7 22.

Everything I see online says it should say P318 but they for sure say B318.

Any thoughts? Or em I just over thinking this?
Author: Bigfritch