This is a prototype for a disc brake conversion kit for the military m715 and its variants. It is a recreation of a conversion kit that used to exist. It would need to be made of metal to function properly. The real version would be welded to the back of a wheel hub and allow a chevy disc brake to be bolted to it. Included are also holes for the studs of the original axle to be removed and replaced. 
This is designed to adapt the original m715 hubs to a ~2011 Chevy Silverado 2500 disc brake that has an 8x6.5 lug pattern and a 5 inch center bore diameter.
The file should be to scale, but I haven't been capable of testing it on an actual truck as I don't have a truck yet.
Created in Fusion360