Both gasket surfaces are important if you want to prevent oil leaks. It is also very important that the gasket at the intake manifold and the baffle tube that goes down into the intake manifold are assembled correctly to prevent oil leaks. Also important is the condition of the threaded holes for mounting the fuel pump. Many have stripped threads.
I have a 59ab fuel pump stand that meets all of these requirements priced at $25.00 + cost of shipping to you. PM or email me if interested.