For those who might be looking for performance (even some non-performance) parts for the older Cadillac big blocks, check out these vendors.
Maximum Torque Specialties (http://www.500cid.com)
CAD Company (formerly CMD) (http://www.cad500parts.com/)

Yeah, MTS is a great company. They offer a lot of Cad 472/500 swap kits into all sorts of vehicles. Thanks for the links!