Your biggest leaks if oil is on the exhaust manifolds would be the valve cover gaskets. Replace them with fresh gaskets and grommets and you'll start living a smoke free drive to work.

If the LIM gaskets are black in color, then yes...I'd change them out with the aluminum framed ones. Those two right there cover motor longevity and the smelly leaks. (Of course while doing LIM's, injector o-rings, SC gasket or UIM gasket, TB gasket, and a can of TB cleaner.)