Bill Elliot was driving for Melling by 1983 so if you are doing an 85 car that would be a good place to start. As far as wheel base an track width I do believe that NASCAR had rules and still do for these requirements. The teams had to make the car match the rule book. I do not know where you got your numbers Also remember that the templates back then were not as close as they are today, and there were not as many for the car to match. Each team had a good idea of how the body was shaped. LOL I hope this helps you a little.