What bolt for this timing cover hole?

What are you guys using for this bolt? Passenger side SB timing chain cover, newer 70+ model. Even with the gasket in place, the water pump snout sits right on top of the bolt head and can not be installed flush to the cover's surface. Is there a bolt with a really thin head-cap I should be using? I bought a set of stainless hex type box kit, but the hex heads are way too tall also for this one little hole. Grind it down? Grind down the corresponding side of the water pump snout? I'd rather not grind anything. Thanks!