I have them on mine with some crappy shackle lift, oprox. 1.5"? I haven't put more than a couple miles on them though. The collapsed and extended length is about the same as other shocks that are sold for 0-2" lift. I tried to ask petroworks what length they sell to go with the ome leafs but didn't get a straight answer. Maybe they know people can get them for cheaper elsewhere.
You might try asking petroworks, they do recommend and sell the red Gabriel shocks, maybe you'll have better luck than me. If you do get that info please post it on here.