On the '71 Charger I originally had 15"x 7" rims front and back with 255/60-15 tires. It looked OK, drive fine, no problem fitting.
For drag racing, I put 15" x 10" in the back with 255x60 MT ET street drag radials, but they look pretty short, but were about the least expensive because they are 27"x 10.5" tires that are commonly used when running a class requiring 27" x 10.5" street tires. I have also ran wider tires and clearance to the front part of the stock leaf spring starts to get tight. I think the 10" wide rims have 5" back spacing?
When I got the Coronet Convertible, I put the 15" x 7" rims on it, and bought some narrower front rims 15" x 4" for the front of the Charger, now with 15" x 10" rear, and using the car mostly drag racing.
https://www.youtube.com/watch?v=7jPszKC29QQ