well I happen to know that the very same tires came on 1970 'Cudas as a special order by the dealership and had to be hand written in on the order form...So common sence is not the reallity here....facts are.
To me, you are saying dealership installed. Common sense will tell you that it would be easier for a dealership to perform the swap then the factory. Tires are a cheap and easy way for a dealership to 'seal the deal'. Picture the truck loads of tires at the factory waiting to be installed. They all got the same ones within the factory order form. The factory isn't going to put a special set of tires on. That was the dealership's job.