Davco 382 coolant/electric heat

You do know the coolant heater bolts to the bottom of the filter and would have to leak through both castings. But it your story and which I believe none of it.

 

That may be why they no longer make the single piece casting with the coolant passages surrounding the input fuel line to the filter.
The filter I was speaking of failed in 1997.
Yes it was 25 years ago and I did not know that they made an add-on heater now because I had no reason to investigate the heating systems since.

 

Don't know about Davco, but my ISX fuel water separator had an electric heating element in it.