What plugs the front of the passenger side head where the exhaust passage is. I thought my manifold was leaking in the front corner but the exhaust is coming out of the front of the head. Filled it with silicone for now until I can repair it properly

 

A small metal plug like a freeze plug only smaller, or an oil gallery plug only bigger. I remember buying a couple sizes and one fit but I can't remember which one. They are available at parts stores. Just measure the hole as well as you can. Just be glad it is not the one at the back of the driver side head. That one is a real pain to get to. I cut a small hole in the firewall.