how much can i shim Lca's

i have a 3'' skyjacker kit on my 89xj. It came with 16" non adjustable lower control arms. I want to add 1 3/4'' coil spacers giving it around 5" lift. Question is how much can i shim the rear Lca bracket to get the right caster? i read somewhere the lca needs to be 16 5/8'' at 5'' lift. Can this be done or is there a limit on how much you can shim it?

The shims come in two sizes.... Part number for the 4mm shim is 52003976, and 52000234 for the .95mm one.

You can stack as many that will fit. I don't recall how much "play" you have to move the CA forward, but it seems to be at least 1/2" worth of room. Recommended range is 5 to 7 degrees. The less the better, so as not to create driveshaft/vibe problems up front, yet enough to get your caster where you need it. It really varies a little bit from XJ to XJ....