I believe that there are three different inner seals for the Mopar Dana 60 car rear ends, one for each size axle. the 1970/71 with the 35 spline axles will use the one for those axles only scope
The 1966/67 17 splines and the 1968/69 with the 23 splines are different ones shruggy

Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)