Diahatsu fourtrak springs are the same width as those fitted to sj/samurai, use a 2" shackle for lift or bush to bush centres around 3" for std lift, needs to be 10mm thick section and braced if 2" lift ones used for strength and with high tensile bolts and lock nuts, bushes can be modded thinner if required, depends on bush type.
Std shackles from sj not worth it as most are knackered when removed.
Vitara has no shackles unless a front live axle has been fitted with leaves, std is wishbone and coils.
Hope this helps.
Cheers.