since i am really not sure i gotta ask. I am planning on lowering the rear of my 55 f100 by removing a few of the leaf springs and dropping the front by putting in a 3 inch drop straight axle. the rear end on my truck is out of a 69 fairlane or comet. thats what the numbers on the axle say at least. without any mods to the truck bed will i be able to run an 18 inch wheel in the back and 17's in the front without any other major mods????