Late Model 3/4 spidles with 6 lug Swaps?

[ChopTop]

Many of you may know my lack of apprehension when it comes to swapping front suspension parts on our trucks. I have a freind who drives one of those late 6 lug 3/4 ton chevy trucks around 90 model or so. I measured the axle on it when it was brought up on this board about swapping the rears. These trucks come with 14 bolt rears and should be the same bolt pattern as many of our trucks. My question is: Why can't we swap the spindle's and rotors onto our trucks? What are some Caliper options with this spindle? Has anyone tried this combo? This would seem like a great alternative to the 5 lug update and use all OEM parts in the process. Can you imagine if you needed a disk in a hurry and the only way you could get one was to special order your 6lug rotor from somewhere across the country? Not me friend. Lets hear your thoughts.