I'm thinking that the answer is right in front of everyone: the drag package cars from Chevy, Ford & Dodge.
Narrow the range of offerings down to blown & unblown.
Allow the blown cars some real tire size & backhalf work.
Call them ProStock.
Bingo, instant 1970 as far as brand participation, fan loyalty, and cars that look like cars.
The existing PS cars could be re-powered, some downforce mandated for safety, and go to Comp.