Those are a good idea, but just a heads up, for fresh water you want the Magnesium pencil anodes. Zinc is better than nothing I believe.

https://www.defender.com/html/zincs_info.html

Yup, Zinc for saltwater. Mag for fresh. Zinc will do virtually nothing in freshwater. The bare aluminum will become your sacrificial anode. FWIW My 1992 AFR heads were still going strong in 2014 when I sold them. Freshwater use. Once you go closed cooling you'll never go back!!

Ryan - you used anodes for the heads/intake on the 383 / I don't remember this.

No, I didn't run anodes on my engine setups. Still lasted that long with plenty of life left.

The anodes I bought are for use in an aluminum radiator on a car, to keep the radiator from corroding.

"Flex-A-Lite developed these zinc anode kits to be installed as a replacement for the drain petcock in radiators equipped with a 1/4 in. NPT bushing welded into the tank (they can be installed in any 1/4 in. NPT hole that is available in the cooling system). For years anodes have been used in heavy-duty and marine applications to protect the cooling systems and its many components from damage due to electrolysis. Flex-A-Lite now brings this protection to you. Today's cars and trucks have many aluminum parts and parts made in combination with aluminum alloy. Aluminum parts may disintegrate from electrolysis in the cooling system. Installing a Flex-A-Lite zinc anode will protect your cooling system from galvanic action by "eating" the zinc rather than your cooling system. Cheap, effective insurance."

I just pulled the intake, to do a cam swap, I also pulled the anode to see what it looked like. The anode already had a noticeable corrosion on it. The aluminum intake and heads showed no signs of corrosion, just a little brown staining from the lake water. I needed the plugs anyway, so I figured what the heck.

Asking again - Would it be possible to do a full FWC system if the engine has an EMI thunder exhaust, extended to dry tails?

Depends on HP. More HP more heat generated that you have to get rid of. Another place to look for heat exchangers is Mr. Cool Marine Products:: Marine Coolers, Exhaust Parts, Anodes, Filters and Cooling Kits

Full systems.

Fresh Water Cooling Kits