When installed, this extra length to the stand-off stud for the later b-body rear bar, would actually lower the position of the bar that ½” in relation to the ground on the 72’s. I’m currently running a later rear bar with the longer stand-offs on my 72’ without any adverse effects.
Still hoping to locate the correct 72’ Dana b-body rear bar at some point down the road.
When these cars were new, the only way to service these brackets was to replace the entire bar assembly, eventually repair kits became available to service the stand-offs which tended to break under certain load conditions. These repair kits used a single bolt clamp arraignment around the bar isolator.