Welcome aboard, looks like your 1/2 ton truck has a full floating rear axles which are normally found on 3/4 ton and heavier trucks. Your spring pack and overloads tell the story, as well as your spring mount is above the axle tubes instead of below the axle tubes which are found on 1/2 ton trucks too. If you have an open driveshaft instead of the torque tube(enclosed driveshaft) that will be the smoking gun and the reason you have the big brakes. Somebody has more than likely swapped out the big brother rear end in your truck, it probably is a really rough rider with all those leafs.

Last edited by sstock; 02/27/2019 2:46 AM.
1953 Chevrolet 3100
261 cu inch, sm420, 3.55 rear, torque tube still,omaha orange, still 6 volt, RPO green glass, side carrier spare, all done
In the DITY Gallery
Video of the 261 running

1964 GMC 1000
305 Big Block V6, sm420, the next cab off restoration