I'm not sure they use the formula any more Ron, but it works out to one car for every 400 feet. Back at champcarstats, checking another era that people get misty-eyed over (1955), there were only 11 races on the schedule. And one of them was the Pikes Peak Hillclimb. 100-milers on dirt only started 18 cars, yet somehow "Big Car" racing was healthier then. Another thing, other than at Indy everybody ran upright Kurtis or Kuzma Offys and everyone gets nostalgic for those days, but today it would be sneered at as "spec racing".