starting a engine thats been sitting for a few year...what to do

Marvel may do a better job of cleaning of rust than WD40 will. It will also protect the parts a little better. Unless the engine had manifolds or headers on it and the rockers were backed off it may have rust on at least one or two bores. Enough that I'd want to make sure there was Marvel in the holes before I turned it over. I'd pour a bit in every hole, then turn by hand wit the plugs out so the excess runs out the holes. Then pre-oil it with a primer while rotating it to veryfy il is getting to the rockers, put the plugs back in, and let 'er rip.