I guess I should have been more explicit. The plumbing question refers to routing and flow.
You're redesigning the thermostat housing to move that boss to the drivers side - ostensibly to make plumbing for intake heat easier. The housing is the source of hot coolant for the heater. Where does the water pump get plumbed into the intake thereby inducing flow?
The approach I took on my build was to have the water flow from front the back through the manifold:
The source of hot coolant is via a tee in the drain petcock on the back of the block:
Flow is induced by fitting a tee on the water pump inlet:
This creates two coolant loops that constantly flow regardless of whether the thermostat is open or closed. One is the stock heater hose loop. The second is depicted above.
Are you putting the heater and manifold one the same loop? Doesn't that result in a heater hose routed over the top of the valve cover?
