So I am finished lapping valves and grinding everything that I'm gonna grind on my resurfaced cylinder head and ready to reassemble it and install it on my freshly rebuilt block. The upper gasket set (felpro) has 12 o-rings included in the set. I can't for the life of me figure out what these are for. I'd assume it has something to do with the valve train since there are 12 of them. I don't see anything like them on my head or engine anywhere.
Anybody?
Bueller?
It's kind of bothering me....

 

Not quite an inch across, and thick rubber? Fuel injectors. (The valve guide seals are "umbrella-type, and slip overtop of the valve guide and have a garter spring on the outside to maintain tension.)

Get a couple ounces of clean fuel and dump it in a cup or small bowl. Toss in the new o-rings.

Strip down the fuel rail, remove the old O-rings. Install new O-rings from the soaking, install the injector.

You soak the O-rings in fuel to make them more pliable, and help them seal more quickly.

 

That makes sense, since the injectors are in another pile that I haven't looked at yet. Thanks!