jdog,
Let me know when you get some numbers. When I built CSX4083 in 1998, the aluminum body was no longer an option.
Another option is Kimmons Coach Works, who makes handmade bodies:
Kimmons Coach Craft of Lake Havasu, Arizona
http://www.csxinfo.net/427cobra/kimmens.htm
Alan Sorkey
Shreveport, LA
CSX4083, The Cammer Cobra