There's a place in San Diego called Southland Clutch that will build you a very strong clutch if you don't want to go mainstream. My 72 has a southland special and the SM465 input shaft bearing is bigtime worn out, turning a heavy truck, the clutch has been in there for years and it's still mean. The pressure plate side is ceramic discs and the flywheel side is some kevlar weave or something. Anyways, they built me a clutch that's good enough for a thousand horsepower for around the price of a centerforce. Then I made the mistake of buying a hayes for the 67 camaro and it's a POS and was more expensive than the southland.