454 thermostat housing gasket

[pschauss]

I bought the three gaskets that I need so that I can replace the thermostat on my starboard engine. The one which goes between the thermostat housing and the intake manifold has four small grommets as shown in the picture below. Any idea what their purpose is? The Description on the invoice says "GSKT/THERMO W/GROUND". I assume that this means that they are supposed to maintain electrical continuity between the manifold and the housing although it would seem that the bolts which hold the cover in place would serve the same purpose.

http://www.ipernity.com/doc/307687/51358588

[scenarioL113]

I guess it is redundant to the bolts.

Bolts that secure engine parts that have jacketed water or raw water are sometimes "gooped" on the entire threads to prevent leaks and I guess. Head bolts are usually handled in this manner and I guess it is possible that the "goop" could prevent metal to metal conductivity which would lead to electrolysis...

I am guessing to be honest but it is prob something along those lines

[Bruce]

That is for grounding between housing as you suspect. While the bolts will generaly do it, some models of engines have in the top cover of the thermo housing or the intermediate housing a pipe thread for a temp sender in which some models have a single wire temp probe of which the ground is important.
Since marine engine are subject to higher corrosion than car engines its a hedge against connection issues.