I have these springs on the front of my Disco, no cranked arms, but I'm running a wee bit heavier than the norm, so you may need some if you aren't going to install a winch, bumper, etc...
'92 Disco truggy (42"s, ZF, dual cases, ARBs, 30 splined, OMEs, Optimas, Warns, Bead-Locked)
'04 D-90 TD5 ST (33"s, tuned, caged, 1/2 top)
'84 Rangie 2 door classic (32"s, OME, ARB bar & M8000)
'04 Disco II stock
'07BMW G650X Challenge (farkled)