I've got the RE XD 4.5 springs on my 88 , hand crafted boomerang shackles on the rear , hand crafted shackles on the front , neither pair of shackles is much longer than stock. It has 33" tires , rubs at full stuff in the rear only , bad enough that the corners are starting to bend. Not a big deal and nothing that a sawzall won't fix , I'm ordering some bushwacker cutout flares and going with 35" tires next year. More lift is not in the plans , I'm trying to keep a low center of gravity , trimming is all I intend to do to make em fit. The flex isn't all that impressive right now , the shocks are limiting down travel , up travel isn't a concern , even with the rubbing issues , it has daystar extended bumpstops too.