I was told to get a 4 wheel alignment on my 1987 760, the last year with the solid axle. What adjustments on the rear are there? There is nothing to adjust, right? So, an alignment on the front is all I'd need if this is true.

The only adjustment on the rear is with a really big hammer and then you are more than likely to knock it out of adjustment. There is really no adjustment except for toe in-out at the front just make sure that nothing is bent and that the mounting plates at the top of the struts are in good shape.