We try to go by correct appearance meaning, if you have a 318 with a 4 bbl carb and intake, that of course never was available in 1970. But the 340 was. Basically I am trying to educate myself without spending a ton of time going over a car. Usually, the judges have about 10 mins or so total to get the car judged and that is with 2-3 judges. 4 if we are really lucky that day.