5.7L Water Heater Connection

[Lift12]

I am working on connecting the heat exchanger portion of my water heater to my 1989 5.7L Mercruiser. The previous owner disconnected and closed the loop, as seen in the attached photo.

This configuration is NOT what the Merc manual (15) recommends. I wonder if anyone sees a problem with the Supply coming off the top of pump as it is now? Would this connection affect the tempeture of the water going to the heat exchanger in the water heater?
My thermostat housing currently has sensors in both sides but I will reconfigure if there is reason to do so.
I appreciate your thoughts.

 

[wrench 3]

I can't see that setup working. The port in the top of the water circulating pump is a return, originally for a thermostat bypass. Is there a port in the intake manifold that you could use? There is usually one in the starboard side forward coolant passage.

 

[Bondo]

Ayuh,..... That's 2 returns, on the cold side,.....

There should be a pipe plug in the intake manifold a couple inches behind, 'n slightly to the starboard side,....
It'll have a square drive, a 1/2" ratchet extension snaps into,....

 

[alldodge]

 

[Lift12]

Thanks guys. I'll change it up.

 

[QBhoy]

As mentioned, that won’t work. There is usually fitting blanks on the upper and lower starboard side front of engine.