A-body 8 3/4 with big bolt pattern axles?

I'm sure those are cut and resplined or aftermarket. Mopar never made a 8 3/4 LBP for the A-body.

That's very possible. Regardless, I'm happy that I don't have to have them redrilled for 4.5"!

Too bad I can't use the 7 1/4 backing plates since I happen to have a set in my car that I soon won't be needing... ;)