couple questions about installing a lift kit

so im about to install my 5in lift and I just have a couple questions.

i got a set of used 3in lift leaf springs that came with a shim. Im going to be adding 2in shackles and running a SYE with XJ front drive shaft. do I still want to install the shims?

I also have a set of upper and lower rubicon express control arms. how far do I want to extend them? how do i figure that out?

a lot of this i've discovered is trial and error. with 5" of lift you more than likely will need some shims, probably 3*-4*. I'd install them, then with the XJ on level ground measure the pinion angle of the rear. Should be 1-2* pointed down.

For the upper and lower control arms, use the lower control arm to determine wheelbase - 101.4". then you can use a combination of upper/lower to determine pinion/caster angle.