Wanted (chrome) gas cap for Duster

slantsixdan said
Three different caps for Dusters: '70 49-state + Canada, '71 50-state/Canada + '70 California, and '72-'76 50-state/Canada. Which does your car need?

Car's a '71 but has had a lot changed before I got it. Are the differences noticeable? I can take measurements, pics of fill tube. (Left the supid thing on pump 2 weeks ago, now no cap!:angryfir: )