I have a 98 Wrangler S, (one of the rear springs is broken). I also own a 05 Unlimited Rubicon. I plan on installing a suspension lift, on the Rubicon, in the near future and want to use the factory springs, from the Rubicon to replace the springs on the S. Will this work? The Rubicon's have a factory lift should this be taken into consideration when buying a replacement lift kit. For example: If, the Rubicon comes from the factory with a 2" lift and I put in a 4" aftermarket lift kit. Would this actually lift the Jeep 4" or add 2" to the factory height?