Been done lots before. You need to move the hangers both front and back, and if you are puttin the 52's up front, I wouldn't take any leafs out before you try it. They are pretty flexy as is and if it is a road going vehicle you may want to keep it a bit firm. The rear will be flexy as heck. You may get axle wrap depending on power to the rear axle.
Check out Pirate4x4 forum. There is lots of good info there. Make sure you do extensive searches first though before asking questions.