Part Number 1971 PVC,Vent Tube Grommet

[Paul C.]

Can someone tell me if the vent tube (passenger side) and the PVC (drivers side) grommets which fit into the valve covers for a 71 LT-1 are the same part number? What is that part number? I assume it was the same part for 1968-1980's.
Thanks Paul

[Patrick H.]

Re: Part Number 1971 PVC,Vent Tube Grommet

Paul,

I don't know the part numbers, but I just went to AutoZone last week and bought replacements for $1.99 identical to the originals I took off a 72's valve cover.

Patrick

[Paul C.]

Re: Part Number 1971 PVC,Vent Tube Grommet

Looked at both grommets again and they are different. Th PCV one is square on top but is not flat--looks like a ramp. The vent tube grommet on the passenger side is square and level. They are obviously two different parts. Any know the part numbers? Don't know if same for 1972.

Paul

[Joe L.]

Re: Part Number 1971 PVC,Vent Tube Grommet

Looked at both grommets again and they are different. Th PCV one is square on top but is not flat--looks like a ramp. The vent tube grommet on the passenger side is square and level. They are obviously two different parts. Any know the part numbers? Don't know if same for 1972.

Paul

Paul-----


Aluminum valve cover applications use different grommets than those used on steel valve covers.

For your application the original grommet was supposed to be a GM #3946862 on BOTH sides. This grommet has a "squarish" top which is NOT angled with respect to the round bottom section. It was replaced by GM #3989348 in December, 1971 and it's possible that your car was actually originally equipped with the 3989348. That grommet is still available from GM.

The grommet with the "squarish" top which is angled with respect to the round base section is GM #3989349. I have no information that this grommet was ever originally used on a 1971 LT-1, but that does not mean it was not. Certainly, it was in the GM "parts bin" and available for use at the time your car was built. It was definitely used for the left side for later C3's with L-82. It sounds like the later C3 configuration with different grommets on each side is what you've found on your car. If these grommets are original to your car, then it may very well be that what's regarded as the later C3 configuration came into use very much earlier. As I say, the 3989349 part number is definitely a "1970-ish" part number and these grommets were used only for aluminum valve cover applications which were unique to Corvette and Z-28 Camaro. The GM #3989349 grommet remains available from GM to this day, too.

Tip: sometimes the GM part number will be found embossed in very tiny digits somewhere on these grommets. You might want to carefully inspect the grommets currently on your car for such markings.

[Paul C.]

Re: Part Number 1971 PVC,Vent Tube Grommet

Thanks again Joe. The #3989349 was on the 1975-1982 aluminum valve cover HiPerf 350's (one side) according to Paragon and #3989348 was used on 1969-1974 350 aluminum sp HiPerf on both sides. Zip corvette has same description. Dr Rebuild has things or pictures reversed. I did not purchase the car new so I can't say what was original. But it looks like the one on the PVC side (#3989349) was incorrect and the one (#3989348) on the vent tube passenger side was correct. Neither of the grommets which appear old have any numbers on them but they are cracked and falling apart.

I will purchase two #3989348 for my 71 LT-1.

Thanks again for taking your time to answer a forum members question.

Paul

[Patrick H.]

Re: Part Number 1971 PVC,Vent Tube Grommet

I will purchase two #3989348 for my 71 LT-1.

Paul

I kid you not - check out the local auto parts store. They are the exact same parts you will buy through a catalog house. I found the "square top - round bottom" style and the plain round style, as well as others.


Patrick

[Paul C.]

Re: Part Number 1971 PVC,Vent Tube Grommet

I appreciate the heads up Patrick. I was able to buy two NOS grommets for $7.50.
Thanks for the help.

Paul

[Joe L.]

Re: Part Number 1971 PVC,Vent Tube Grommet

I kid you not - check out the local auto parts store. They are the exact same parts you will buy through a catalog house. I found the "square top - round bottom" style and the plain round style, as well as others.


Patrick

Patrick-----


Absolutely. The ones I've seen in "bubble packs" at auto parts stores appear identical to the originals, save for the fact that some originals have the tiny, embossed GM part number on them. I don't think the current GM pieces do, though.

[Paul C.]

Re: Part Number 1971 PVC,Vent Tube Grommet

The ones I purchased have the part number #3989348 embossed on them.
Paul

[Joe L.]

Re: Part Number 1971 PVC,Vent Tube Grommet

The ones I purchased have the part number #3989348 embossed on them.
Paul

Paul-----


Do you know if these came out of current GMSPO stock or might they be from older stock?

[Paul C.]

Re: Part Number 1971 PVC,Vent Tube Grommet

The person I got them from bought them 6 years ago from a GM dealer that was going out of business. He has a couple left. email me if you want any.
Paul

[Joe L.]

Re: Part Number 1971 PVC,Vent Tube Grommet

The person I got them from bought them 6 years ago from a GM dealer that was going out of business. He has a couple left. email me if you want any.
Paul

Paul----


Thanks for the offer. However, I have quite a few real old stock examples of all of these. I believe they have the part number on them but I haven't the energy to go and dig them out. I'll check soon, though, and if they don't have the number I'll get back with you.