i got a set of ord shackles sitting in my garage, but i havent installed them because im unsure how that 1 degree in caster will affect handling.can i use shims to bump the axle back up? i know you cant use blocks up front, not sure about shims. or if its even necessary.id like to straighten out the u-joint angle. also i just put my 3in lift on and my front driveshaft has only about 3/8 of an inch of clearance from the crossover exhaust. when i jack up the truck at the frame they touch, should i have a muffler shop re bend a pipe? dimple it? or what.