"Fray" has gotten to be a sort of generic term for what I would call SS T-Jets. If you are actually planning to attend the Fray at Ferndale you should check their rules. I doubt that many clubs use rules that are exactly the same, so you should check with whaterever group you plan to race with. Most clubs have their rules available online, if you have any questions about those rules you should contact an officer of that club to get the best answers. It is better not to have to make changes to your cars after you get to a race.