To those that don't know-the 76 A body caliper used little larger pistons than the 73-75 A body. I think they were the same as the F and later M body calipers. Probably doesn't really matter but probably does?:lol:
i'm *pretty* sure just the casting is machined larger. there's the 2.58 and the 2.75 is the "big one" and that's used on pretty much everything else.
ma mopar did some wild things, but splashing the pot and casting all new calipers would go well against their penny pinching ways in the bean counting days.