Guys if he’s talking about a ‘73 he’s not talking about Kelsey Hayes brakes that share the Mustang brake pad.
EBC offers pretty much their entire line of pads for the 73+ single piston calipers, and there are quite a few semi-metallics from the major names in brake pad manufacturing.
Sacrificing your stopping power to have your rotors last longer is just flat out dumb. Would you rather preserve your brake rotors, or your bodywork and possibly your health? Because it’s a lot easier and cheaper to replace brake rotors. And if it’s 73+ rotors we’re talking about they’re readily available in several different levels of performance and quality from multiple reputable manufacturers. So trying to preserve a set of 40k mile, decades old rotors is just unnecessary.
OE compounds for these brakes are 50 years behind the times. For a show car you never drive, whatever, run some dried up dusty decades old brakes. For a car you actually want to stop? Not a chance.