Only one engine. The 92-93 300SD had the same 3.5l engine as the 94-95 S350. Essentially the same car. Possibly the same 603.971 engine as in the 90-91 350SD and 350SDL which are the 126 body style.

It'll be interesting to see if the OM606 will go into a 140.

Sixto
91 300SE
87 300SDL
83 300SD