So far I haven't had any hint of hydrolock, or other obvious signs of coolant entering the combustion chambers. (knock on wood!) But I agree that I need to get this looked at no later than early spring, when it gets hot here in Sacratomato and the cooling system must be at 100%.
Now, about the ALDA - I've always wondered how hard it is to R&R. What does it connect to inside the I/P? If I wanted to "tweak" it to enrich the mixture a little, I could remove it, turn the screw, and then re-install? It would be nearly impossible to turn the setscrew & locknutwith the ALDA and intake manifold in place!
About the glow plugs, I know then can be done with the manifold and injecotr lines in place, but it sure looks like a multi-hour bugger of a job. Thankfully MB designed an oil leak at the #2 intake runner that develops over many thousands of miles, so when glow plugs are needed often the intake gasket is too. What a convenient coincidence!
I'll be doing this on my b-i-l's 1987 300D sometime this month, as a matter of fact... already have the gasket, plugs, and vac servo from Rusty (Atlanta Wholesale Parts, 800-741-5252.)