Down the rabbit hole researching cars again - as one does. Been on a kick of collecting brochures for the first generation Mercury Cougar, C3-C4-C5 Corvettes, first and second generation Camaro and Firebird, European Ford Capri, and Fiat X1/9.
I found it interesting that the Cougar brochures directly called the car a 'sports car'. I was surprised by this. It could be marketing mis-nomer or appropriation. Nowadays I think we consider these a muscle car or a GT car if you are of that mind set. But not 'sporty' per se.
I also read that they were successful in SCCA Trans Am racing. So much so that Ford pulled the plug on the Mercury racing team after the first season or two in order to allow the Mustang to prevail.
They are the same car under the skin - the only dynamic differences would be the longer wheelbase and the longer front and rear over hangs. Would affect high speed stability and polar moment of inertia I guess.