I dont know what the real differences are but I do know that the engine in my car is from A 300SD and My car is a 300D, therefore Im running on a 300SD engine with A tranny from a 300D. With little problems whats or ever. Was there any real difference between the the 300SD engine from the 300D engine, it seems like the brake booster and vacuum that goes to injection pump and to tranny is different from any other 300D Ive seen. If possible can someone with a 1984 300SD or 1982 300D scan some pictures of there engines, I can't find anyone with the similar setup I have. I have a 1982 300D. Also is it true that the 300SD engines were stronger and able to rev higher.