Here is an exert from a SWCS newsletter that was emailed to me on 2/9/09, written by Roger Bourland, in regards to the GT class for the SWCS:
You asked for it and we listened. This is the fastest growing class in the country! We are going to kick off this season offering this class as a SPEC Class. Later in this newsletter you will find the rules that have been adopted for the inaugural season for this exciting class. On behalf of the SWCS Committee, I want to extend a BIG Thank You to Juan Blaylock for doing the research and providing the basis for the rules that we are starting this class with. If you have.........
As further proof to back up Jspeed, see the attached PDF file of the first newsletter from February 2009. The rules in the newsletter were for the Spec class but rules for the Open class submitted at the same time and the Open class cars were run along with the Spec cars LeMans-style at the races.