Do you recommend dressing the MACE TIMING COVER GASKET KIT TO SUIT HOLDEN ECOTEC L36 L67 3.8L V6 with anything prior to assembly? or are they suitable to be used as they are

We usually recommend applying the RTV gasket sealer to the surface of the engine and timing cover where the gasket mounts. A little dab of RTV sealer in the corners, where one gasket meets another, can be helpful for preventing leaks.