I bought a full gasket kit from Thunder Racing for my '03 4.8, and noticed they sent me graphite head gaskets, whereas the originals were MLS. In doing a search I read that graphite gaskets are not good for boost, and do not seal the water passages adequately on newer engines. Also they are marked with "5.7", but measuring with a caliper shows the cylinder hole diameters match the marks left by the originals. Should I send them back?