dually axle width\'s ?\'s What is the difference between a 14 bolt FF from a dually and a single rear wheel? Also on the front IFS of a dually and a regular 4x4? I am swapping axles in my 1/2 ton yukon and need to now if I can buy axles from either? I have a 14FF don't know what it came from though? Is the width different or what?