Probably pretty good but not better than modern cars. In the 2000s one of the car magazines tested top trim (big engine, race package, etc) classic muscle cars

Probably pretty good but not better than modern cars. In the 2000s one of the car magazines tested top trim (big engine, race package, etc) classic muscle cars on modern tires and they put down respectable numbers, not better than 00s cars, but respectable. Suspension and chassis stuff hasn't come all that far since the 90s so high end cars of that era should be able to handle very respectably compared to modern stuff. The differences are more apparent at the low end. Modern crossovers handle very respectably for what they are. Obviously modern stuff will always win in a straight line because power levels increased massively over the past 20yr.