As Billy stated, around the Midwest, 95% of people will run a 40" car. I know back in the day the 41" was more popular out West due to their tracks nature of usually being heavy. A 41" car around here is a little harder to hook up when the track gets slick.

Most of my years running with the Law Brothers was in a 41" car which we got working really really good regardless of track conditions. Kevin Thomas also won a ton of races running 41" cars right up to when he retired.

I always called our 41" car the Cadillac as it never did anything stupid. The rougher the track the faster we went but when the track dried off we simply made changes and were just as good. I did run a 39" car for a bit and talk about wheel stand city!