The real question would be what was the old back spacing and what is the new back spacing? Get spacers that match the difference or change the turning stops as described above. I personally hate spacers but they serve their purpose sometimes.
'88 YJ with SOA and SYE and a bunch of custom crap from BWF in Chesapeake.
'97 XJ on 8" lift, double triangulated rear, long arm 3 link front, Eaton/60 with 5.14 gears.