Are you at stock height? Four inches seems like too much. At the very least, if you are trying to level it out, make sure you measure your fender to ground distance. Fender down through the center of the wheel to the level ground for all four. Ideally you want to do it when you are near empty of fuel, then again with a full tank, and as much weight as you might possibly have inside, (or a rough equivalent if you tow). This will at least tell you how much you need to drop to level it out.
If you have already done this or are trying to look at the sky, then don't read the first part of this post.
and yeah you will need new shocks or shock extenders too. If you don't change the shocks too, you will be riding around with your shocks already compressed 3-4 inches. You would blow out your shocks quickly, but that wouldn't matter much because you would probably have about 1-2" of travel before you bottom them out. With them already partially compressed, instead of bottoming out when you hit a speed bump at good speed, you would bottom out when you hit a seam between concrete. Drop shocks will give you less suspension travel. Shock relocation brackets/shock extenders will let you keep your full suspension travel, (and should work on your current shocks), which means not buying new shocks if yours are good.
