I'm glad that helped, but I feel like I need to clarify something for you.
You can't add the front Gross Axle Weight Rating (GAWR) and the rear GAWR and arrive at a Gross Vehicle Weight Rating. (GVWR, or GVW) The two types of ratings are mutually exclusive.
Your 1-ton truck was equipped with a HO72 axle, not an HO52. The combination of gearset, bearings, and brake equipment made it an HO72, which has a rating of 7,200 lbs. on it's own. If you were to properly equip a chassis and vehicle to support that kind of payload (uncluding the weight of the vehicle and chassis) that is the maximum that axle would be capable (with a safety factor engineered in) of handling, which is not only carrying, but also stopping. The same goes for the front axle.
The GVWR is determined by looking at the capacities of ALL assemblies and adding a bit here and subtracting a bit there to arrive at a rating that both satisfies safety, and regulations.
The HO52, again rated at 5,200 lbs. is basically the same axle, but again the combination of gears, bearings, and brakes, reduce the rating of the axle by 2000 lbs.
Now, here's something to think about, and may put into perspective how it is that combined GAWR does not equate to GVWR.
My 1955 1st series 3600 is equipped with (2) HO52 axles, originally w/4.57 gears, currently with 4.11 (or 4.10, I'm not sure of the tooth counts). The GVWR on the door tag is 6900 lbs which is the highest rated 3/4 ton for that year. Now, this truck is an upfit, which predates factory 4x4's by a couple years in Chevrolet. If you were to combine the two axle ratings you'd come up with a 10,400 lb rating. That'd never happen. When the factory trucks started being released, the front driving axle option only added 600 lbs. to the gross vehicle weight and the combination of spring packs, wheels and tires could vary greatly from truck to truck, thereby changing the GVW in stock configuration greatly.
So, your truck has an HO72 in it's original form with 5.14's and 1 ton brakes. If you want a 4.11, you'll be pulling them from a 20 series truck, most likely, not a 30 series unless the diff has been swapped already.
