I am wanting to lower the rear end of my 2 wheel drive Super Crew 2 inches and I have 2 questions. First, I have seen the DJM lowering shackles and the Ground Force lowering shackles. Other than price is there any difference (ie quality)? Next, I know this has been addressed in other threads but, by lowering the body and bringing it closer to the axle, wont the shock be compressed 2 inches (assumming a 2 inch shackle) before any load is added to the truck?