I needed the spacer for the PCV (1965) but removed the hoses. Instead of plugging the fitting at the intake I tapped it and used the tap for a water pressure sensor. Originally the hot water was to prevent carburetor icing but where I live that is not a problem.

 

After doing some research, I found out that running the water through the spacer also acts as a heat exchange, by warming up the fuel it helps it atomize it better in the combustion chamber, leading to a better air to fuel mixture, resulting in a better burn. Doesn't give that much more power that I can tell, buy hey, I feel smarter repeating it.

 

After doing some research, I found out that running the water through the spacer also acts as a heat exchange, by warming up the fuel it helps it atomize it better in the combustion chamber, leading to a better air to fuel mixture, resulting in a better burn. Doesn't give that much more power that I can tell, buy hey, I feel smarter repeating it.

Correct. It is more of a cold air measure. The fuel mixture is heated allowing the gasoline (atomized) to stay in suspension. The heat riser feature is another cold air feature. This (heated spacer) was later replaced largely with heated air inlet.

You would want to keep it for an everyday (every season) driver but maybe consider bypassing it for a performance engine.

 

The guys with the big six seem to always add this to their performance manifolds to maintain optimal drivability, especially when cold. I'd keep it unless all-out performance is your main goal.