Plugging smog holes on 302 heads

I'm asking those that have been there/done that with 302 casting heads, what's the easiest way to plug the emissions holes that are below the exhaust ports on 302 casting heads. I didn't have to deal with these guys on the old 675 casting heads that I replaced. I'm sure those that have done the 302 head swap could share an effective and possibly easy way to close these things up for good. I already had the heads bolted on when it was brought to my attention that they need to be sealed. Thx all.

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