> Wouldn't it be better to use the copper-red colored Permatex on the gasket
> and mating surfaces just to be sure?
> 

A proper gasket should seal 100% by itself. Throwing Permatex into the
mix kinda adds an unpredictable wildcard to the equation. My old 280Z
was held together with permatex, baling wire, and epoxy putty-- most
of it "field expedient repairs" I never re-did properly because I was
young and adventurous (that's pronounced "poor and foolhardy").
Nothing I ever put sealant on, either in combination with a gasket or
sealant alone, ever held as reliably as a proper gasket alone on
smooth metal torqued to spec. When you think about it, it makes sense.
The relatively soft sealant is never as tough as the gasket material,
and in places that don't need the flexibility, really the best it can
do is create a weak spot.