I have been through this problem with my LJ. I run BDS 3" springs and 5100 Bilsteins, the fronts are perfect. I would be interested the 4" progressive rear coils from Currie but they are to tall for me. I also wonder how the 3" Nth progressive springs would work for me. I went for the Air lift bags and it cured the constant bottoming completely. I am very happy with high speed and low speed performance,I have ran them for 3 seasons and have no issues at all. I have had Air lift or Firestone air bags on 5 different Vehicles some for 15 years and only had to fix one air line that was 10 years old. It would seem the bumpstop is trying to pop the Bag but not yet anyway, and the almighty Flex seems fine. The timbren bumpstops seem like a easy way to add some improvement, the air bags require spring removal to drill the hole in the spring seat for air line.
I can recommend the Bilstein 5100's, I had hydro shocks installed and the Bilstein's made the Jeep way more stable and comfortable. Shane at Bilstein steered me away from the generic 5150's..
86CJ project org. owners
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