Just an FYI on silicone.
Should you be "Conservative" with silicone, or apply it "Generous/Heavy".
Here's what a radiator repair shop had to say....
The most frequent causes of radiator tube blockage is the
excessive use of silicone for water pump and thermostat gaskets.
The overflow or excess of the silicone to the inside
cannot be cleaned and eventually some of this will break free
with the water flow and carry on into the radiator,
in many cases lodging in the tubes and blocking them.
Silicone will not dislodge or dissolve once in the radiator
and dismantling it is the only way of removing the silicone
from a blocked tube.
Remedy, use proper gaskets with a good recommended
gasket cement.
