XTR was a term used in the 80's, and into the 90's to show it was one of the top of the line models. The term was used on all of Winchesters line, not just the 70's. You will see a few 94 XTR's as well.
At that time they offered some budget versions. There are featherweights made before the 80's and after the mid-90's that are still top quality rifles that were made before, and after the XTR