I was afraid to just buy wheels and tires from catalogs.
Went to a local small tire shop that also sold Crager wheels. Talked to the owner and discussed problems with returning wheels that won't fit. After we agreed that he would not charge me for wheels that would not fit he got on the phone and measured numerous times. After a couple of days he had Crager wheels that would fit
my 37. Fitted three different rear tires until we got a size that fit in the rear fenders. Long story short, go to a tire/wheel shop and put the risk on them to get the right size.
Al V.