Just wanted to report some pleasant surprises resulting from a recent very thorough engine and compartment degreasing of my 81 300SD.
I believe this is the first time it's ever been done. (in 190,000 miles)
With the engine cold, just about everything was degreased and rinsed thoroughly. The linkages were also cleaned and then lubricated with white lithium grease.
(Please tell me if this is a no-no.)
I steered clear of the turbo and surrounding area.

1. Temp now hovers around 180 consistantly - used to read slightly above it.
2. Engine seems to run smoother and quieter.
3. Most interestingly, the jerky shift from 1 to 2 has smoothed out considerably, and the flare from 2-3 is nearly gone.

Was hoping the slight rocking of the engine at idle after sustained driving would be gone, but no such luck. But overall I am very pleased with the results.

Plus any leaks and seepages can be spotted right away.

Just one more thing - replaced the air filter and there's less smoke belching at takeoff.
(This pointer was mentioned in one of the posting in Tech Help. Thanks !!)