Take a look at any of the modern supercars including Viper, Corvette ZR1, Buggati Veyron, even the Challenger SRT8; all use multiple piston calipers.
The '73-'76 calipers use a single piston caliper design.
Ive always wondered about that Vs29H1B, i currently have the kelsey hayes 4 piston caliper setup in my dart but i was thinking of changing it to the later style disk brake setup because i have a furd 8" rear end with the 4 1/2 bolt pattern but im thinkn otherwise. Does anybody know if theirs any real difference between the earlier and later brake setup in stopping distance? I figure a 4 piston caliper setup would stop alot faster than the single piston caliper setup would but like to get some opinions on that.