Third gen’s are still preferred for autox by alot of people simply because of their weight. Making power isn’t a issue, and the suspension on them isn’t all the different from later F-bodys.
The later cobras are good, but not that great. The 5.4 shifts alot of weight to the front. Also the IRS wasn’t designed for the car originally, so the geometry on it isn’t ideal (compared to other IRS cars). In fact its been done several times where mustang guys have made a live axle mustang handle better than the IRS. All that said, we have a guy locally who runs a Convertible supercharged cobra thats got a few mods. Handling wise it does pretty good since he picked his parts well (I’ve driven it, slides awesome lol).
As for the Vette, handling wise even a C4 can put a hurting on most cars. A C5 or C6 is just rubbing it in :burnout: Chris is right to about the classing stuff. But if you don’t really care about classing mod away!