best body for road race setup

Well when we compared back to back, Dave's early fastback (66 b-cuda) seemed at least as rigid as my notchback even though mine had connector and his didn't. We run the same tires and rims. I think there is a shaped channel up through the roof to make up for the lack of braces behind the back seat. You may recall that in my car, the floor where the bottom of those braces attached had to be rewelded and reinforced several times. OTH this may have as much to do with the quality of the original build as the design...

Again it comes down to the rules for the class. How much bracing and caging is allowed? Are aero devices allowed (vintage rules generally the answer is no)