redwing, sign up for the SEMA newsletter and they will help you stay informed about our hobby. I've written several letters to senators/governors due to them being informative.
...correct me if I'm wrong. Several years ago I thought the trailer tires were a odd ball size, as in 15 1/2, to keep folks from running the tires on vehicles???? Perhaps redwing used the tire and rim as long as the bolt pattern was right?
....but I must admit, back in the mid 60's, before the changes, I ran 6 ply trailer tires on my 56 coupe. They were about slick/worn out, and would really bite on the old slick "tar roads" around my home town. Won many drag races with them.
So, what is the skinny on trailer tires and rims?