I plan on using the positive retention seals part# 72527 along with the o-ring style. Can I use the positive retention style on all of the valves, or are they just for the intake side? Also I called Napa and Autozone about the o-rings, they are 59 cents a piece at NAPA and at Autozone they were like $12 for the intake and I think $17 for the exhaust. What is up with that?, that is quite a price difference.

 

You can use the positive seals for both intake and exhaust.

Sounds like the prices they gave you are for the positive seals, not O-rings. A full set of O-rings (all 16 would be identical) should be around $2 or $3 max.

The O-rings are pointless if you use real seals, I would not spend any money on them, they don't work.

 

i use both, i figure for a dollar or two what's it going to hurt.

 

The GM positive seals are different, too. They are identified by a brown or white stripe (white is exhaust IIRC). They are both PTFE seals, but the exhaust seals are designed with lower edge pressure and a higher temperature material.

 

The Autozone prices they quoted me were right, that was for the positive retention seals and they come with the o-rings. The exhaust were more because of the higher temp material the seals are made of as Vader stated.

 

Vader:
Do you happen to have the GM p/n's for both the intake & exhaust seals you mentioned? Are these seals retrofitable back to a '88 5.7L engine? Do the top ends of the guides need to be reworked to accomodate these seals? What are your thoughts on running both the o-rings & the positive stem seals?

What is that? 4 questions, not counting the last ones?

FJK

 

FJK,

Yeah, that's about four. You get sixteen more...

The upper ends of the valve guides would probably have to be machined for the seals, since I believe the L98s did not have that provision.

I don't have the number for the seal kits themselves, since I've acquired them in either the rebuild gasket set or head gasket kit (including a head gasket, valve seals, intake gaskets, rocker cover gaskets, etc.). Your dealer should be able to get you a part number for th eseals alone.