i just got a gasket set and im puting my heads back together. well in the felpro gasket set it has teh little o-ring style valve stem seals. im wondering if i have to use the umbrella style seals with these on the guides or if they jsut work by themselves? also how do i install them? the directions just confused the crap out of me wiht the plastic installer? thanks alot

 

The o-rings are the factory type seals. You install them by putting the valve in, putting on the spring/shield/retainer, compressing the spring, put on the plastic thing, slid the seal over the stem down to the retainer, remove the plastic thing, install the keepers, let the spring up. Pretty simple, eh?

The umbrellas are a little better. The best are the "positive" type that require machining of the guide to install. They make a "positive" seal between the guide and stem.