Yes you can. I did this to my truck only a few months ago. The 3/4 ton outer knuckle looks to be a little heavier duty than the 1/2 ton. You can actually leave your 1/2 ton outer knuckle on and just swap the spindle, hub, rotor, caliber mount and caliber.
Did it go together nice and easy? You did something wrong.Will have to do it again.[img]/wwwthreads_images/icons/crazy.gif[/img]