The AI in AC really struggle with old race cars. Whatever flaws they have mean they are more off pace in certain cars than others because of how they drive I guess. They are further off pace in the 250 GTO than they are in the Griffith. As an example at Silverstone 67 the Ferrari can do 1:43.2 and IIRC the Griffith is very similar but just a tiny bit quicker where as the AI do 1.44.5 in the TVR and 1.48.6 in the Ferrari.I am surprised that the GTO is considered as the faster car. When I did a track day with the AI, the first 5 cars were all TVRs with more than 2sec advantage over the GTOs.