Valve guide seals LA 318 ?

I have a 69 318 w/stock heads. Well my question is it has stock heads 318 with double valve springs. Im assuming not original. The umbrella seals are gone most likely the junk I found in the oil pickup. I bought a felpro gasket set was rebuilding my heads and the seals won't work with the double springs. Looks like the head wasn't machined for any other seal type and the three seals that were left are hard as a rock. Anyone have a part number for an umbrella seals small enough for double valve springs. Thank you