Sorry if I wasn't clear. The front axles using the 8.75" bolt circle were available in both 5,000 Lb. and 7,000 Lb. capacities. The 5,000 Lb. Axle had 5 studs and the 7,000 Lb had 10 studs. The 7,000 Lb. Axle was optional on the C60 and standard on the C70 trucks.
The rear axles were 15,000 Lb. and 17,000 Lb. and the 17,000 Lb. Axle was optional on the C60 and standard on the C70. In the early 70's, I believe there were several years when the C50 was rated the same as the old C60 and the C60 was rated as the old C70. This ended when they figured out that users thought that the C50 was a lighter truck than the Ford F600.
We also had some problems with the fact that Ford and International used a 17,500 Lb. Axle, while we had only a 17,000 Axle. There were times that a literal interpretation of a spec could force us to quote an 18,500 Lb. Axle and become uncompetitive.
The hubs were what were different and there were different hubs with the 5 and 6 and 10 studs for the front axles with the different ratings and for the rear hubs with the different ratings.
Hope this helps to make sense.
