There will be a couple variables. Placement of the shock tower will depend on shock length, droop & compression. I think I have roughly 6" ish of lift. I used the full height of the SD shock towers. ( the bottom of the SD tower was flush to bottom of frame) and with how I mounted my shock tabs on the axle this put my 14" shock right mid stroke. 7"up travel, 7" down. So, there is not a right answer for every rig. You will probably be safe with a longer than nessasary shock, like my 14". ORD's tech guys will line you out with the right answer for YOUR truck I'm sure.