For the love of all thats holy dont put double shackles on the rear suspension setup! Just run a single shackle thats about 7" eye to eye and move the rear hanger back a few inches. MR4x42u runs that setup with a traction bar and it works pretty damned good. If you go double you'll end up changing it later chances are.
You dont need to modify the front hanger but Id still highly recomend that you do. The stock hanger has a good chance of coming off the frame under a good hit on a rock since the steel is weekend by all the welding in that corner causing embrittlement. Plus if your going to do it do it right to start with. Move the front spring location ahead about 1" with a 2" drop to correct the castor angle and to pull the shackles ahead a bit. Move the steering box as far ahead as you wish to go when you mount it, you'll thank me later. Marlin has the best deal for quality extended brake lines going. Id also recomend getting Marlins shock hoops for the front and getting at least a rs9000 shock. For the front shaft just build one out of 1 1/2" and 2" square tubing. Its way cheaper than having one done proffesionally and it will stand up to anything you can throw at it. Plus if your not going dual cases right off the bat you can make it long enough to still be used once you have duals with no worries.
