Need help comparing 1979 Camaro Z28 vs 1977 Firebird Trans Am

I have both the 1979 Chevrolet Camaro Z28 and the 1977 Pontiac Firebird Trans Am and I wonder which is better as S1 (890+) road racer with rear wheel drive and all assists turned off. IRL they are both General Motors 2nd generation F-Body cars, very similar, but I don’t know how this fact translates to FH4 since I’m a new player.

With the 3rd generation F-Body cars, it was easy. The 1990 Camaro IROC-Z (RIP 5 million credits) has better track and tyre width options compared to the 1987 Firebird Trans Am GTA, which is quite noticeable when running Goliath at S1. Is there a definite answer for the 2nd generation F-Body cars?