1973 duster fit 20"s??

good point Adam, The question was:
"anybody know if its possible to put 20s on a 73 duster?"

I imagine they would fit with the proper back spacing.
It would stand to reason that if the stock wheels were 14 inches with like 80 series tires then 20's should fit with like 20 series tires.

for example
if your stock tire/rim was 175/80/14 you would have a diameter of 25.0 inches

if you had 195/30/20 your diameter would be 24.6

so in short YES.. just watch the back spacing.. good luck. it's your car. build it how YOU want it..