What A-body did this 8 1/4 come out of?

No worries! ;)

So the 8.25 is 51.5" flange to flange? Interesting. That's the exact same measurement I pulled off of the BBP 7.25" that was in my '74 Duster originally. So, that probably is an A-body 8.25, especially if the perches look to be original at 43". The gear ratio wouldn't be matched up to a 340 car, but who knows. Same with the brakes. I'd say they were swapped out for the 11x2's, but man, if Commando66 has seen a couple more 8.25's with 11" brakes that may just have been the thing. Ma Mopar has been known to just add stuff if it was leftover. Like how all kinds of '71 A-bodies (and E's) got rim blow wheels without being optioned for them otherwise. They were discontinued for '72, so I guess they were just using them up.

It's interesting that the flange-flange measurement doesn't match the 8 3/4's, that screwed me up when I figured the backspacing for the first set of wheels I bought for my Duster, I assumed the BBP 7.25 had the same dimensions as the 8 3/4, but they don't. I wondered what the 8.25's were, seems like they might match the BBP 7.25.

Just sent an axle housing to Moser to be shortened. BBP axles are longer after the bearing, so the housing needs to be shorter to keep the same track width. Uses standard BBP wheels and backspace which keeps the wheels centered in the wheelwell, without thinking.