Sticking a few pins into the bottom might give you a fighting chance.
I really hate to carve away at the deck. We have/had a nice 427 here that somebody installed adjoining sleeves with no step and a tight press fit. Split the deck between the bores. Then they pinned the deck crack in an effort to save it without any success. No matter what we tried for head gaskets we could not get that poor thing to hold a seal - seemed fine cold but sucked water as soon as it saw any load and the head started moving around.