offset bushing cam sprockets are legal to remedy this, but not always available readily.
Not legal on a dual overhead cam. OK to use an offset key at the crank, but not at the cam. Someone correct me if I'm wrong. (of course this is stupid thing, any single cam motor doesn't care if the adjustment is made at the top or the bottom. Some dual OH cams get affected different amounts by decking so those should be the ones allowed to restore cam timing at the cam)

But OTOH, if you can restore things to spec (blueprint & balance), why can't you reset the pin on the cam?