4crawler, did you move the mount in the back for the double shackle or no? Some people say you dont have to move it if you are going 63's and a double shackle. Would there be any benefits moving the shackle mount a few inches back with a double shackle?

 

w/ 56" springs, I retained the stock shackle hanger and used the upper shackle to move the mount back about 3.5":


That top shackle is normally bolted to the frame:


To me, it was easier to build the double shackle on the bench and then bolt it in place than messing with relocating the shackle hanger. I have yet to try unbolting the upper shackle.