crank seal
when you split the engine check the crank for straightness your local machine shop can check it for you for small money I think. And it a wise thing to do when you have it out. I had a engine that suck air from the seals. The seals looked good but the repairman told me it had been leeking because the crank was not straight. Maybe not the problem in your case but better safe than sorry and better to do it when your engine is split than to have to split it again.