Usually, with a 1.75" (44.45mm or 4.45cm) spacer you'd add a 1.5" lift shackle. A shackle lifts half the increase in length. Therefore, if you wanted to gain 1.75" lift in the rear as well, your shackle would need to be 3.5" (88.90mm or 8.89cm) longer than the stock one. Commonly available sizes are usually only 1.5" lift shackles, except for one or two...I think the Rock Krawler shackle being one of the longer ones.