Bill, Your right they could have used lighter weight materials. GM does this with the Corvette and it would have been nice if they translated that over to the Camaro.
The FD is the 92-02 RX-7 body. This car is considered a better chassis than the new RX-8 and a LS engine with the tremec 6 speed fits perfect. It's also a lighter car than the RX-8. Here is a link to a company that make a complete conversion package.
http://www.hinsonsupercars.com/s-1-m...-fd-93-99.aspx