While both the 10.5 and 11.5 may have the same GAWR, if you check deeper I'm sure you will find this is due to the tires limiting the GAWR. However, if you check the manufacturer's rating for the axle, you will see the 11.5 has a higher capacity. Axles are also have a torque rating though that info is usually very hard to find.
On my Dodge, the 11.5 GAWR is 6,190# due to tires yet the axle itself is rated for 10,300#.
AKSuperDuty, sure do wish they still used Dana axles but haven't for a few years. The quality of the Dana was worth the little extra money, but when you are selling thousands of trucks, the dollars add up quick.
