intake gaskets (and should i block the heat crossover)

so I bought a felpro gasket kit for my 75 360
it came with 2 sets of intake gaskets, one steel one fiber (or whatever that cardboard stuff is)

im using a weiand action plus aluminum intake
what gasket should I use?

and would it be a good idea to fab a little block off plate to close the heat crossovers going into the manifold (I was thinking 3 thou shimstock)
or is that best left alone?