Hi from England... I've had a KJ for just over a year. Reading this guide has been fantastic and has inspired me to completely renovate my poor old 80k miles 2.8 CRD Liberty (Cherokee over here).
So far I have:
Got the rims re-powder coated, replaced the leaking turbo inlet hose, swapped out the factory stereo Nav for a Kenwood, K&N, fumoto valve, power flow stainless exhaust, performance ECU flash, 2 new glow plugs, new ECR pipe, changed tranny fluid, front diff oil, transfer box fluid, rear diff oil and fitted off-road rear diff cover. Yesterday on the motorway at 70mph I got 35.4mpg so very pleased and working out what to tackle next!