I'm working on a 1983 300D. Where can I find a diagram of the water flow thru the mechanical systems (water jacket, heater core, etc)?

I'm modifying the system to include a heat exchanger for alternative fuels......

 

This is what is in the Factory Service Manual.

The Hot coolant comes out of that bent Hose closest to the top of the Oil Filter Housing (the one that is in the way when you do an Oil Filter Change) and goes towards the Heater Core. After that I am not sure.