I believe your wheels are either 6 or 6.5. Be aware that some tire shops will not mount radial tires on the old riveted type wheels unless they are in exceptional shape(no rust/pits or loose rivets.
Some people say they are running radials on the riveted wheels but is it worth it to risk a wheel coming apart? eek

There is enough good in the worst of us and enough bad in the best of us that it does not behoove any of us to criticize the rest of us.
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Be yourself. If you are ever lost, It will be much easier to find yourself if you know who you are!