L71 Valve Guide Seals

[Mark F.]

I am replacing the valve guide seals on my 67 427/435 L71. Does anyone know the best place to get these and the part number?

Thanks!

[Joe L.]

Re: L71 Valve Guide Seals

I am replacing the valve guide seals on my 67 427/435 L71. Does anyone know the best place to get these and the part number?

Thanks!

Mark------


GM seals are still available under GM #460527 but GM list for over 5 bucks/each.

You want Viton (fluroelastomer) seals and not nitrile. I'm not sure if the current GM seals are Viton but I think they are.

Otherwise, Mahle #SS45296 seals are Viton.

[Mark F.]

Re: L71 Valve Guide Seals

Thanks for this information Joe! Greatly appreciated. I have in fact found a Chevy dealer who has 18 of them, even though their data base now says they are discontinued. One question, I do not have the valve springs off yet, but do you know if the seal consists of only the hood or is there the hood and an O Ring that goes into a groove on the valve stem? The micro fish does not show an O Ring but I thought I should double check just to sure.

[Joe L.]

[Duke W.]

Re: L71 Valve Guide Seals

Does this engine still have the first design single spring/damper valve springs or have they been replaced with the second design dual spring?

If the first type you should replace the valve springs since the first design is prone to failure. The second design is no longer available from GM, but I believe Joe has identified an aftermarket replacement with nearly the same specs, and they may require a different type seal.

Duke

[Joe L.]

Re: L71 Valve Guide Seals

Does this engine still have the first design single spring/damper valve springs or have they been replaced with the second design dual spring?

If the first type you should replace the valve springs since the first design is prone to failure. The second design is no longer available from GM, but I believe Joe has identified an aftermarket replacement with nearly the same specs, and they may require a different type seal.

Duke

Duke------

Yes, that's a good point. If the engine does have the first design springs, they should definitely be replaced. The second design springs, not used in PRODUCTION until late 1969 at the earliest, used a special valve spring cap (retainer) with an attached umbrella seal. These must be used with the second design springs. In GM SERVICE the springs were only sold as a unit which included the springs, cap, and seal, although the cap/seal was also sold separately. While the second design springs were available in the aftermarket, as far as I have been able to determine the special cap was never available in the aftermarket. The second design seals are available, though.

[Joe L.]

Re: L71 Valve Guide Seals

A little more info on second design valve springs:

GM #3970627----2nd design spring + cap + seal DISCONTINUED

GM #3964264----2nd design cap + seal DISCONTINUED

Aftermarket replacement for spring: Melling VS-940

[Lawrence S.]

Re: L71 Valve Guide Seals

Joe you are a wealth of knowledge!

[John P.]

Re: L71 Valve Guide Seals

Hello Joe, are the Sealed Power VS-708 springs also a replacement for the GM#3970627? Thanks for your input, John

[Joe L.]

Re: L71 Valve Guide Seals

Hello Joe, are the Sealed Power VS-708 springs also a replacement for the GM#3970627? Thanks for your input, John

John------


Sort of. The GM #3970627 was a valve spring UNIT consisting of a valve spring of unknown part number(never available from GM separately) and a valve spring cap/seal assembly of GM #3964264.

The Sealed Power VS-708 is a replacement for the spring but was never supplied with the special cap/seal. Sealed Power instructed that the VS-708 spring had to be used with the GM #3964264 cap/seal.

The VS-708 is discontinued.

[John P.]

Re: L71 Valve Guide Seals

Hello Joe, Can I remove the original snap fit seals on my #3964264 keepers and install the Mahle SS45296 seals? I know the Mahle seals do not snap into the keepers as do the original however are they the correct replacement seals for these keepers? I will be using these with the VS-708 springs as stated in previous post. Thank you so much for your advice, John

[Joe L.]

Re: L71 Valve Guide Seals

Hello Joe, Can I remove the original snap fit seals on my #3964264 keepers and install the Mahle SS45296 seals? I know the Mahle seals do not snap into the keepers as do the original however are they the correct replacement seals for these keepers? I will be using these with the VS-708 springs as stated in previous post. Thank you so much for your advice, John

John------

The Mahle or Fel-Pro replacement seals are the best you can do. I have also noted that they do not seem to retain as positively as the originals but I believe they will work OK. As far as I have been able to determine, GM never offered these seals separately.