so many different valves...

[RustBucket]

SB chevys only use an o ring at the top of the valve stem just under the keeper from the factory. Many times they get brittle and break apart. You can get umbrella seals and even positive seals aftermarket that fit over the valve guide and work better. As a personal preference I always use the o rings as well when I put positive or umbrellas on a sbc.

I ordered a head gasket set and it comes with umbrella seals as well as o rings. Thanks boss. I wasnt sure what i was looking at. Safe to say that this head is probably never worked on.