Help! Timing belt broke, fixed head, now 4 o-rings that I can't find where they go

[JustCoz]

I'm working on an '06 Aveo that a friend of mine picked up with a broken timing belt. So I pulled the head off and sent it to the machine shop to have the valve guides replaced (all 16 were broken). The problem is, the machinist (his buddy) went on vacation for 3 weeks. So here it is, almost a month later, and I'm trying to remember how to put it back together. The biggest issue is, I have 4 o-rings, about 1/2" OD, that I can't for the life of me remember where they came from or find a home for. Can anyone help?

EDIT: The injector rail was never removed from the intake manifold, so they're not from injectors.

Another edit: I actually have 6 of the old o-rings, and the head gasket set came with 14 new ones. I don't think they came out of the top of the valve cover, because there are o-rings there already. I cannot find them anywhere in the GM Service manual, either.