Don't forget the outside of tires measurement,
You probably want the new axles to actually fit under the truck and in the fenders.
Driveshaft and brake hoses will be pretty simple.
If the brakes are much different than your old ones pickup the matching master cylinder when yo get the new axles.

Also check your caps lock key,

Grigg

•1951 GMC 250 in the Project Journals
•1948 Chevrolet 6400 - Detroit Diesel 4-53T - Roadranger 10 speed overdrive - 4 wheel disc brakes
•1952 Chevrolet 3800 pickup
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"First, get a clear notion of what you desire to accomplish, and then in all probability you will succeed in doing it..." -Henry Maudslay-