I had a 83 300D turbo, was and is a good reliable car. Bought an 86 300SDL, California car that moved north. It has so much more power than the 5 cylinder that it would never do for me to go back. If it were me I would look at at least the cars through 87 and try the 6 cylinder before you make the plunge. This particular car has over 241K and runs very well.

Ric