LS engine cylinder head end studs

What are those studs on the bottom right and bottom left of my engine block that you place the gasket on that hole it is place while so you then can place your valves on? I can't seem to find them on the engine I am going to rebuild for my truck. I am attaching a screen shot from your "how to build a" 5.3 LS - Part 8 series and circled the part. If it does not attach then let me know in your reply. It shown at 5:23 mark, bottom left of cylinder 1 or right of cylinder 7.