If you build it right you can put 2 1/2 inch wheel spacers without hurting anything.  My friend had 2 1/2 in ws and 37's and jumped it quite a few times.  He didn't do anything to the truck.  It ran good any everything untill he sold it.  BTW,  the more backspace on the wheel will put more stress on the bearings.  It's like having a wheel spacer on it.