viton valve seals?

[v30crewcab]

anyone have a part # for the viton valve seals that would go on a 80's 350 without machining? the positive seal type is what I'm looking for. I used some I had laying around on another engine, but here wasn't any part # on the package, and I want to put some on my other motor as well. thanks.

[MikeB]

What year engine? Early small blocks need to have the guide bosses machined to accept positive seals. Chevy eventually switched to positive seals, but I don't know the year. I do know they were used by the mid-80s.

BTW, what are the symptoms you're seeing?

[Motherfrog402]

I can tell you that my '79 L-82 Corvette needed to have the heads machined, in order to accept the new viton seals, so it had to be after that that they changed to the newer style head.

I had my heads done in '97, so I don't remember the part number, sorry.

[SkinnyG]

I didn't want to pay for machining, so I used factory o-rings AND Ford-style umbrella seals.

[v30crewcab]

I put the last ones on a 82ish 305. had to push them on hard but it worked good. it was the kind with the metal ring around the bottom. guess I will do some more digging. not going to machine them I know theres some that fits! just gotta dig up the part#.

[v30crewcab]

looks like sealed power mv-1888 is the individual # for them. going to make sure they fit in a few days. haven't got it apart yet, still working on tower notch and 4link.

[MikeB]

Originally Posted by SkinnyG

I didn't want to pay for machining, so I used factory o-rings AND Ford-style umbrella seals.

That's worked well for me in the past. In fact, just the o-ring seals work pretty well until the guides start to wear. However, most people don't understand how to install the o-rings. And of course, the valve stem must have two grooves. Regarding the umbrella seals, I don't remember the type I used, just that they were for 11/32" valve stems. However, if the valve guides are worn and the intake is sucking in air on the intake stroke, then positive press-on seals are the answer, especially for the intake valves.

I once used a Fel-Pro top-end gasket kit for mid-80s 350s that came with 8 positive seals and 8 umbrellas seals. As I recall, the postive seals were for intake, the umbrellas for exhaust.

On a similar note, the postive seals on my new GMPP Vortec heads are different for exhaust and intake. My guess would be the exhaust seal is a little "looser" to allow more lubrication of the guide.