No the warn hubs and the factory auto hubs are different hubs I have a set of auto factory hubs on a work bench at home I keep forgetting to throw out.
On my f350 it had ...on the fly 4x4 that you could activate by the switch on the dash. , it also has manual locking hubs in case the auto lock (vacuum) went bad. If that system is working correctly once you put the switch in 4x4 and it is working you are in full 4x4 until you turn the switch back to 2 wheel drive.
I use to have a f350 that was full manual....get out and turn them 4x4 hubs and you had to shift the lever on the floor to shift the transfer into 4x4 high and low.