There were m463 units made with the Ford Racing logo on top, and PI ports. Wouldn't be surprised if they didn't change the coolant opening when they did. Some came with NPI ports and owners carved them into a PI shape also.
That number on the top, I don't remember mine having one there. I'll have to look later. Mine has the BQxxxxxxx number stenciled between the two rear plugs, and some have other markings there. I may have seen something new.today.
Astangthang,
What do you mean by what year blower?
They were kits available from 1998-2004 ish, give or take. I'd imagine any m112 rebuild kit would work, but honestly there's not much to rebuild.
FYI, it's really common for people to believe these were m90 blowers. Between the Thunderbird SC, the later roush m90 blowers, and a magazine article that incorrectly id'ed these as m90's, it's become a common misconception. The m112 is a much longer rotor, it's obvious in person though.