[Saito]

Not specifially a hot rod question, but I'm putting valve seals in an '89 Chevy pickup with a 305 for a friend in need. The seals look like the o-ring type. Is there a groove the o-rings sit in on the valve stem or do they push all the way down to the guide? Its been 20 years since I've done this and I honestly forget. Thanks.

[LATECH]

The O rings go into the lower groove of the valve stem as they seal oil from running through the retainer at that point. The keepers grab the upper groove to hold the retainer on the top of the stem.
Also dont you have umbrellas for the guide tops? Or did yours not use them?

[Saito]

Thank you for the reply. I don't know about the umbrellla seals. Advance didn't list them so I'm assuming it doesn't use them (I hope!). I'm going to be doing this Friday so I don't have it apart yet.

[BOBCRMAN@aol.com]

89 SBC's use a positive seal (FelPro Blue) that presses over the valve guide on the intake side and a white plastic umbrella on the exhaust. Plus the O-ring on the upper stem. Replacing just the O-ring seals will solve nothing. A waste of time. The later engines did away with the O-ring altogether as GM's existing inventory was depleted. Using the positive seal system exclusively.

[Saito]

Made sure I got the postive seals along with the o-rings. Thanks for the info!