[67drake]

Originally Posted by Beers

I think OPH nailed it. ‘73-‘77 A-body.

Looking at your photos Schurkey, and the ‘75 cutlass photo below, I can see how that bracket has been cut apart to separate the control arm and the shock mounting, and then welded back together on this differential to earlier 68-72 layout.

Attachment 637991

I’ll have to check the overall width again to get a more accurate measurement, but it’s about 55” to the inside of the axle flange (this diff has been converted to rear disc, so no drums to check overall width). And it’s about 7.5” between the insides of the mounted upper control arms (I don’t have another 68-72 A-body diff to compare this against so don’t know if this is a lot wider).

Here’s the measurement inside flange to inside flange of the 8.5 I pictured earlier. I also just double checked an 8.5 that is from a 71 or ‘72 Skylark, and it’s measurement is identical to this one I pictured.