FYI
Those are Kelsey Hayes, 4 piston caliper, disc brakes, used on the A body cars from 65-72.
And they are 4 inch, small bolt pattern, NOT 4 1/2 inch.
And the caliper mounts to the Spindle, or knuckle, as it's can be refered to, also, not the Hub.
Those are special bolts.
A member here, Hemidart67 has repoped them for sale, but he now might be out of stock.
Do a search on him.
But they are 7/16 x 20 x 1 3/4 inch in length, if you can find regular grade 8 bolts to use, in that specific length, and diameter and thread pitch.
Look here.
I'm going to bookmark his posting, for my future reference, also.
http://www.forabodiesonly.com/mopar/showthread.php?t=305427
If you measured, and are indeed 4 1/2 inch bolt pattern, then someone had a machine shop drill the rotors and hubs, out to that bolt pattern, or bought Ford Mustang rotors, and had them remachined internally, to be used on those Mopar spindles.