The 1-ton uses a Bendix brake which requires a more complicated mounting setup vs the simple plate for the 3/4 ton Delco brake.
The 3/4 ton brakes are rated for 7200 lbs GVW which is right in line with the '56 1-ton truck.
The first conversion I did,
1-ton Dodge disk brakes uses a Mopar version of the Bendix brake rated around 10,000 lbs GVW. Mopar uses a mount that works with a 1/2" plate but it has other problems as discussed in the other thread.