Any thoughts? 04 lowered and hitting driveshaft
 

Buddy of mine had an 04 that he lowered 3" in the front with lowering springs and in the back used 4" blocks and removed a leaf spring from both sides. For as long as I knew him it never gave him any issues minus a somewhat rough ride and not being able to go over some of the bigger speed bumps some places like to use but a couple years ago 5 of us tried to take a ride in it and even tho it would move it made this AWFUL noise. I just bought it and have been trying to conquer the problem myself. I read around a little and have installed the belltech nitro 2 shocks in the rear instead of just the regular stock ones and it made it better but still get the rubbing. At this point I am wondering if taking out the one leaf spring from either side and having 4 12" subs in the back since he first got the vehicle has caused the remaining springs to lose some strength and support causing it to sag more and rub. Any thoughts or ideas would be greatly appreciated and thanks in advance

The sole purpose of a shock absorber is to dampen the action of the spring. It does NOT affect ride height. The spring determines the ride height. You answered your own question... Removing a leaf from each side weakened the springs to the point where they are not strong enough to lift the body up where it belongs.

Thanks for the input! As you can most likely tell, I'm still somewhat new to understanding how the suspension works but I'm determined to learn and to fix :)