Front hubs should be same for 3600 and 3800 single wheel.
Wheel bearing size change during the AD years, this makes a difference in spindles, not sure if hubs changed too.
I did a fair amount of research in the parts book and the only difference in AD 1 ton rear axle, brakes, and hubs for single and dual wheel trucks is the stud length, that's it. No problem bolting single wheels on your rear axle that had duals.
No idea about Dodge wheels, just try them and see.
