Originally Posted by Willy Mo
buy a 2x4
That sums it up pretty well. lol. Especially for John up there working on a 2010. '08+ 4x4's are already the same size as a coil spring 2wd of the same gen(Gen4+)(pic below as proof). So all you need is to remove the 1.5-1.75" rear block and bingo! You're the same height as a coilspring 2wd. You CANNOT swap the front suspension...its impossible to fit that coil spring in with the CV in the way. Plus, the entire front frames are TOTALLY different between torsion bar and coil spring. If you're wanting to lower a 2010 4x4, you bought the wrong truck.
DisturbedESV's '08 4x4 vs. '07 2wd coilspring
As for lowering minimally a 2wd Edge/Sport or 4x4 truck, as noted above, 2" is about tops then you start running into ball joint angle issues and CV issues. BUT, this same theory is basically what's already done to '08+ 4x4's. So you may run into those BJ issues with as little as an inch drop.