Well, you would either get a 1984 or a 1985 300SD. The 300 SDL replaced the 300SD for 1986-1989. And the 350 SD/L replaced the 300 SDL for 1990-1991. Confused yet? I drive a 1983 Gasoline 380 SEL with 185,000 and it still runs strong. But the diesels are even more durable. If you want some really good answers on maintenence I suggest you go to the w126 forum. The model year 300SD you are interested in is a w126 car. Though the 300SD did make a comeback as a w140 car in 1992.