Your car has to run on tires it would have come with originally
Sounds simple, right? You can visit their website for full information, but essentially you can bring any old muscle car of your choice and run it as long as it looks completely stock. The engine must be one that was available in that car originally in size and displacement and must have a stock sounding cam (along with several other stipulations), but it does not need to be numbers matching. The tires must be of stock variant as well - meaning you're likely going to be running a bias ply tire.
The people competing in this series have really taken their creativity to the next level, and that is the purpose of this article. Joel Nystrum has built what appears to be a stock 1967 Hemi GTX, and is running sub 11 second quarter mile times with it......on bias ply tires. He was the first MOPAR in F.A.S.T. competition to do so. The car is not an original Hemi GTX though ( it's actually a small-block Satellite dressed up to look like a GTX), but per the F.A.S.T. rules this is perfectly acceptable.
As you may guess, getting a big car like a GTX to run a 10.92 second quarter mile is a quite a feat - especially without the aid of traction bars, sticky tires, and a wild cam. Joel did it though....and a lot of other guys are having just as much fun as he is. Below as is a link to the buildup of his car (including pictures) from bangshift.com.
If you are a fan of keeping things original but still need to scratch the "modify to go fast" itch, this may be just the ticket for you. Have fun, and way to go, Joel (and all others racing in F.A.S.T.)! Thanks for the inspiration!