01-03-2011, 07:51 PM
well, most nice leafs will have that built in. it is necessary-because you have to keep the pinion at the right angle to the transfer case. usually about 1-2 degrees under inline with the driveshaft. with all this said...you might have to install the leafs first then,check how much of a degree shime you will need. I didnt have to run any with my BCBronco 11 leafs,HTH
77 built 306,Trickflow Cam/Alum Heads/dome pistons/10:1comp,nv3550,duff long arms,3.5" lift,family cage,protofab rear bumper,twin sticked, and 35KM2'sG.D.I.