If you are indeed referring to the cylinder heads .... and the port on the front or back ... that is the thermactor port. You can get plugs for them from TFS or even Ford. Couple bux.
If you are talking about freeze plugs in the block ... I agree with the above.
I'm pretty sure the stock heads have a freeze plug in the ends of them. I'd still pick up some plugs instead. A complete set to do an entire engine is less than $20, and I'm willing to bet most parts stores have individual plugs for much less.
Wow stock heads have freeze plugs in them..huh. I never messed with my stock 95 so I never looked. And the current one I bought with eddy heads and now I have AFR's so I had no clue.