I am in the process of installing coilovers on my 1989 740 GL. When torquing the spring nut to spec it snapped as seen in picture. Is there anything i can do, next steps, etc.

 

How tight did you think you needed that upper spring support plate to be? It simply keeps the spring from falling out from the top.

At this point someone will need to weld that nut back into position - you can see it was only spot welded on 4 corners - so it was not designed to be "torqued" to any value probably more than 20.

At what are these "coil overs" that you speak of? Are they simply lowering springs on the rear and fancy strut/spring replacements for the front?

 

Yep.....What Hoonk said......Re weld it and do not over tighten/torque it.