1973 duster fit 20"s??

Sure I'm putting 21.5" on the back of my Duster. OH WAIT, I was talking about tire width. My bad... LOL
Seriously though the problem I keep seeing when people put 20's on there car is it gets out of proportion with the tire width, you'll have a 20" rim and a 10" tire and it looks like a wagon wheel, unless they have it mini tubbed and can get some decent width meat under it. If the wheel wells are stock I think the 17-18" rims with a little more sidewall look alot more in proportion, but that's just me. Like others have posted it's your car build it how you want.