Welcome. As far as the lowering kit, you may consider a DJM 2-4 Pro Drop. This kit uses lower A-arms to drop the front which keeps your king pin inclination the same as it would be stock and it will not put the ball joints in a bind. And because it uses A-Arms, you won't lose turning radius as you would with a lowering kit that uses spindles. As for the rear, it uses shackles and hangers and you keep your stock coil and leaf springs with this kit which maintains a smoothe ride. Also, I recommend using Bell tech Nitro Drop 2 shocks with this kit. This is the setup I use and it rides almost as good as stock. People have a tendency to fall asleep in my truck on a regular basis when I'm not racing or blasting my music. Don't worry about that 4.8L cuz it is a lot stronger than you think. Check out my sig and if you happen to see Quik on here, he's got 700rwhp on a 4.8L and I think he still has stock internals. Good luck and feel free to ask this 4.8L anything else