I finally got around to adjusting the valves on the 84 300 D. I have put over 10k miles on her myself. I have every service record and dont see a valve adjustment entry. Well the car has always been fast but did not idle worth a puke when cold. Never much smoke and always started.
When I did the valves they were tighter than a old Banker. After adjusting, the car started right up and idled so smooth I almost fainted. It was Cadillac smooth. WOW
I never knew the old 5 cylinder could do it. It is nice not to stop at a light and feel like you are in a paint mixer.
So get out there and adjust those valves.