Correct, however there is another entity running called the F.A.S.T. series that has branched off from this several years ago, and they run a class called "Factory Stock" which is basically the same thing as the Pure Stock racing running assentially the same rules and tech.
However F.A.S.T. has several races throughout the year at different venues, so it's easier to plan and attend, and it's always fun to see the so called "ringer" cars as some of you guys are calling it, those would be the F.A.S.T. cars or "Factory Appearing Stock Tire" cars that Bruce is referring to.
For more info on this group check here...
http://www.fastraces.org Their event schedule is likely to have something nearby most of you anywhere in the midwest.
Matter of fact you'll see another one of Mahoney's ram air birds on the front page, this one obviously setup to run the F.A.S.T. series.