It all depends on the quality of the kit. If your doing a 6" lift that generally means your also doing bigger tires, bigger tires will often rub on the front lower trim or back by the mud flap area. That results in cutting out the areas that rub and sometimes that isn't even enough on sharp turns. Bigger tires also put more load on the brakes and its easer to overheat/warp them. Bigger tires also put more load on the steering and suspension, you wear out tie rods and ball joints MUCH faster and its hard on P/S pumps. The extended shocks that come with many of the kits are usually not very good quality and wear out quick and ride like crap.
Now, back to the kit details. Does it come with brackets to extend the brake lines and wheel speed sensors or new longer brake hoses? Does it have the brackets the drop the transfer case? If not its going to tear up U-joints. Also does it come with new idler and pitman arms to correct the steering angle?
The bottom line is that lift kits are hard on trucks, the better the kit you buy the better you will be in the long run. Eric
