M50B25 Engine Cooling connections

I've been drawing up some diagrams of the donor cooling system connections to try and understand the flow of water. Not sure if this is correct. Pretty important to understand as I'll be removing the heater and throttle body connections and adding in a header tank as the Marlin rad doesn't have it build in like the BMW did.

 

How the coolant flows inside the block and head is an even bigger mystery

Done