/6 170 exhaust manifold swap

If you're talking real light sanding....yes.....that's fine. Just enough to get a smooth, flat surface. I don't use any sealer on the head surface. The manifold is supposed to move and flex a bit when it heats and cools so you can't mount it rigid. I do use some CopperCoat or High Tack on the metal gasket between the manifolds though....and anti-seize compound on all the nuts, bolts, and studs.