Sorry for the long delay I have been working a ton of hours, but here's what i did...
The Front springs from the JK will fit the Tj without any modding and you will not gain any lift but you will gain stiffness. So plan on buying some 3'' spacers from ePAY because you will need spacers to level out the Jeep.
The shocks require just a bit of modding. The TJ Shocks have two bolts that bolt down to the frame and the Jk shock just have a bolt going threw, so you will need to swap out the grommets, this is easy to do. And that's it for the front.
Rear Shocks and springs: The only issue with the JK rear springs fitting the TJ is the bump stops on the TJ. To get the springs to fit you will have 3 options which are...
1. Cut the springs so they will clear the bump stop (not a good idea)
2. Heat the spring to open it wider so it will clear the Bump stop. This method is fine but one must let the spring cool down naturally on it's one, DO not help it!
3. Just purchase smaller bump stop. This is what I did.
Now the Shocks. You have two options for fitting the JK shocks to your TJ.
1. Take the JK shock to your bench grinder and grind off a little metal from one side of the Jk shock until it fits into the TJ shock mount.
2. Just take a heavy bar and just open the TJ shock mount just enough to revive the JK shock.
And thats it! The Rear springs will give you a modest lift, close to 3" this is why you will need the 3" spacers for the front springs or else your Jeep will look goofy. So when it's all said and done, you will have a cheap 3" lift and a much stiffer ride in my option.