^ possible but unlikely at only 10psi. If you have an aluminum head and run the wrong coolant you can put small fissures or holes throughout the head which may weaken it.

In most cases its just a blown HG. A pretty simple fix if you have a helms and some basic tools. Are you getting any white smoke out of the exhaust?? Is your coolant level lower?? Don't drive it in this condition as you could overheat and warp the head for sure, or worse the block. You won't always have oil in the coolant and coolant in the oil it depends on pressures and other things. Usually if your HG is blown the resoivoirs level will not go down but the coolant will be going into the oil through the HG. So make sure to check your coolant level.

I have blown many a HG.