My cj5 has original springs that are very worn out. All the shackles are shot and the shocks. In addition, one rear spring pivot bracket is rusted out. There may also be damage to the frame where the front shackles go through. I won't know precisely until I take it apart. I am considering adding weld-on shackle mounts under the frame for the front and keeping the front shackle location to the rear of the front tires. I want to run 31" tires. Since all this is being replaced, this would be the time to add lift springs of 2-2 1/2 inches. Original spring packs have 9 leafs all the way around. Has anyone converted their early frame to the below the frame shackle mount? I know this will lift the front maybe an inch. Do I need to shim the axles for a 2-1/2 lift? Lots of questions, I know.