While replacing valve cover gaskets I thought I would also do the valve stem seals. My local auto parts store only has a hard plastic type seal which appears to be the type on the motor now. Most seals that I have installed on other motors have been a soft pliable rubber not hard plastic.

I can see where the current seals tend to ride up on the valve stem since they do not get seated and it seems to me that this would allow oil to get below the seal, get drawn down the valve stem, and thus negate the purpose of the seal. Is this a problem on these motors? Is there a better seal to use?

Thanks,

Mark

 

They are probably teflon seals.
My 77 460 has the original rubber umbrella seals on it. They are original and still work fine after 180,000 miles.