Well, just so everyone knows, I did use the search function...
Here goes,
I adjusted the valves on my 84 300SD on Saturday to eliminate the smoke and power loss issues. Success!!!
Problem... I still have a rough idle. Well, looking back, I think my inexperience on these engines might be showing itself. What remember seeing was that the timing chain seemed loose. I did not think much of it at the time, but I could move it about 1/2 an inch to either side. I think that this might explain some of the noise I am hearing from under the hood, and also that wierd "rough spot" while under mild deceleration.
What think ye? Timing chain replacement?
BTW, I am using the DIY procedures from this link.
http://dieselgiant.com