Sway rar links replaced about a month ago on my 81 300D are at each end of rear factory/stock sway bar. The links are
Z-shaped, about 5" long and stand vertically immediately inside of each rear wheel. Middle of Z is somewhat flat with mounting bolts at each end forming top and bottom of Z. Mounting bolts on mine were worn, loose and very noisy - squeaking, rattling, etc.
Are you sure yours has no sway bar?
91 350 SDL. 81 300D