8 3/4 Question

Picking up a rear end on Saturday. The seller sent me some pics and something looked strange to me (I've circled it in red). I believe this rear is from a 65-67 B body (59 1/2" wide, from drum to drum). I'm going to see if I can get by with using some backspacing...

I've never owned an 8 3/4 before, but I'm used to the shocks connecting to a plate in the leaf spring area. Is this some sort of modified suspension?

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