The rear should be plenty high enough already unless you just want to raise it a little for that extra fender space. No, the Bilsteins will not work on your model year truck. I don't know a lot about it but my understanding is that you can achieve a nice level simply my cranking the torsion bars on your truck. Also, not having the coilover suspension means you can run a wider tire with less worries about clearance of the upper control arm. How wide are you wanting to go? You have a size in mind? I'm pretty certain you could run 35s with a torsion crank. Another guy on here just put 295/60/20 Nitto Trail Grapplers on his 2004 with no issues. That's a 34.5" tire. That anywhere close to what you were thinking?