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Tech / General EngineIs your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
Valve seal question. 1987 350 L98 iron heads 14101083.
Are these the right seals for these heads? Are these considered "positive" type seals? They appear to be Enginetech S2926 seals.
I don't recall the shop saying the guides were machined or not for these and it's not on the invoice. Does this style of seal need the guide boss cut down?
No o-ring on the valve stem either. Should I add it anyway or will that starve the guide for oil since it needs a little anyway? Most seem to say it is not necessary with positive type seals but didn't the factory use the o-rings along with positive seals on the intakes? I know they did on exhaust but those were umbrella.
Any advice appreciated.
Yes those are the "positive" type seals. If they fit your guides, the guides don't need to be machined further. They make different sizes of those, I'm not sure what size those particular ones are, but I do know FelPro makes a size that fits unmachined stock guides, so maybe those are like that too. You can mic your guides and look up the seal specs to see.
The stock O-ring seals are a total waste no matter what. Not sure why the factory still bothers, they don't ever really do much of anything. Get rid of them. They're just a useless additional bit of fiddling during assembly, that accomplishes nothing. Same for the "umbrella" type: useless. Use the "positive" type on both int & exh, as shown in the photo.
