Since your classic car was built, there have been many changes to car technology. Engines have become more powerful and more economical, interiors now have air-conditioning and airbags as standard etc etc. With regard to Classic Cars, the biggest changes have been to tyre and suspension technology. If you were to put a Ford GT40 on a racetrack with a Ferrari 360 with similar BHP and the same driver, the Ferrari would lap faster. If you replaced the suspension and tyres on the Ford for modern versions, the difference would be a lot less. This technology is available today for your classic car.