[Badger]

Even before considering the material for the driven disc I'd be sure you consider a sprung hub. For your application I believe that organic material both sides is best. With the weight of your car you could easily use a stock clutch disc from a high performance Mustang. The sprung hub is often shunned because "racers use solid centers" but years of experience has shown that sprung hubs make for less shock loads on the transmission and help match revs when shifting. Badger.