Advice anyone??89 xj lift

Hi There I have a 89 4 dr xj, 4.0, auto. I currently have a 4" procomp lift installed: (front coils,shocks,sway bar extensions,rear add a leafs) After I installed it it seemed fine, after my first trek the back end sagged 3 inches.I threw in a set of 3 inch blocks in the rear which leveled the truck out. In the last few months in has continued to sag leading me to believe the blocks and add a leafs are a stupid idea and I need a new spring pack. My goal is to get 33's under her. What is required to do this? I'm thinking aftermarket leaf pack with shackles and coil spacers in the front??I recall the coil springs to be a very tight fit on there own never mind another 2 inches. Will longer front arms be required and adjustable trac bar?Trying to do it on a budget without totally cheaping out. Any help,part numbers,etc would be cool! Thanks for takin the time.

I would by new leaf springs for the rear and a shackle just because its not modifing stock equipment they are designed to keep their hight with wear and tear. you could fit 33's with your lift but you would need to do some triming or cut out fender flares. but if you want more hight go to a six inch skyjacker runs 33's with no mods just came out last year with a value flex kit for the six and they also have new springs and shackles.