Nail head head gasket and rebuild?

I tore down my 56 322 after discovering my oil and antifreeze are mixing. When I pulled the heads the center water passage hole (between the center bores) was "punched" out in the gasket. My new set does not have a hole there. Which way is the right way to reinstall them?
Also if anyone has dos or don'ts when it comes to rebuilding this particular motor I would greatly appreciate tips. I am aware that I don't need to put hardened seats in the heads.
The plan is to replace the cam and bearings due to wear. And possibly bore over from slight scoring on the cylinders. This is going in my 56 Buick. Just a cruising car, not a hot rod by any means.
Thanks, Justin

 

I hope you indexed the flywheel, because nailhead Buicks have equally spaced hole in the crank which means you can turn 6 positions and it will bolt up, however only one way is correct. The others will cause a vibration, sometimes severe. I know this very well. Also, any water jacket holes that aren't dedicated to a purpose are a source of internal leaks. Be sure you have product for your applications.

 

Yep, index was marked.