Go to the wreckers and measure one up?
Or go for another option that you know fits. There are Whiteline swaybars on ebay for good prices, also RA40, MA45, RA60, RA65, MA61, SA63, RT142, ST141 and AE86 REAR swaybars will fit.
VN swaybars are probably huge and may lift your inside rear wheel. At the very minimum the mods to fit it will be buying the correct size swaybar to diff mount bushings, but apparently the VN rear swaybars do fit AE71s/KE70s.