5 on 4" Discs on a '65 Barracuda. Year/car?

Gotto disagree to some extent redness, multi-piston calipers are used extensively in everything from high speed racers like formula one to jet airliners, it's all about surface area and therefore force trying to stop the disc from turning. I would agree that there can be a problem with the multi-piston units when one piston siezes in the bore which just means that every couple of years you have to remove the pistons and clean the bore and piston of rust and crap.
My biggest concern when I said that Kelsey's aren't the greatest for drag racing is I would prefer larger discs and calipers. Also the design of pistons on both sides of the disc trying to "squeeze" the disc to stop it turning is more efficient than first pushing on the side of the disc with a single piston and forcing it against a stationary pad. JMO

Terry