well for a start i doubt you mean the head, as
1) would be pointless to chrome the head,
2)most of the stuff in the head is either friction fit or damn near it, with mating faces having to be exact, and
3) you cant see ,most of the head when all the bits i.e. manifolds and that are attached,
i think you mean the rocker cover, if so make sure it gets prepped properly, and that the rocker cover to head mating face is kept flat and clean, as otherwise you will have the mother of all oil leaks on your hands,
but good luck mate, as a bit of chrome under the bonnet is never a bad thing.