you wanting the kelsey hayes 4-piston calipers too? honestly the single piston calipers are a better setup anyway, parts and expense wise. anyone priced a reman set of KH calipers lately? OOOFDAH!!!! plus finding rotors is nearly impossible too.....
I have owned plenty of both and without a doubt I prefer the stopping capability of the Kelsey Hayes disc brakes. Even my 6500 series rollback uses multiple piston calipers on all four wheels. The only drawback to the A-body Kelsey Hayes brake system is the small bolt pattern wheels but that can be solved by having a big bolt Mustang rotor re-machined to fit it. The key to Kelsey Hayes four piston calipers is to use Dot 5 synthetic brake fluid.