4x4 valve cover grommet sizes

[HeloCrewChief]

Does anyone have the valve cover grommets sizes handy? I’m having a heck of a time finding the one for the right rear air to air cleaner and the oil filler tube. Haven’t been able to find some at the local auto parts store.

[geunther]

I believe the part number is 3989344 at least for the right rear. I think you can find the size if you look up that part. I found an NOS box of them (4) but I think there are others out there that will work.

If you can't find any, I will have an extra.

Not the ones I bought, but some others on eBay.

[tj1970cst]

I think I found some on Amazon. Might have bought 4 and returned 2 with the free returns feature.

[HeloCrewChief]

For anyone that does a search in the future, I’ve attached pictures of the three correct grommets you will need for 4x4 valve covers. I just got the installed and everything fit.
Posted via Mobile Device

[geezer#99]

It might help if you explain the difference between normal and 4x4 grommets.
Is there a difference?
Could save someone getting the wrong ones.

[Accelo]

The large one is the oil fill tube grommet.
PCV grommet for the left side.
The last one has to be the tube for the air intake from the air cleaner on the right side.

[HeloCrewChief]

No offense but, I thought I already helped quite a bit. Just pulled 3, 14 hour shifts so this is about all I’m good for! Pretty obvious the differences between 2wd and 4wd engine compartments. Anyway, still hope this helps someone.

[CS1972]

HeloCrewChief..............good information, will save me the effort of figuring it all out.

Thanks!

[Classic Bowties]

Originally Posted by HeloCrewChief

I’m having a heck of a time finding the one for the right rear air to air cleaner and the oil filler tube. Haven’t been able to find some at the local auto parts store.

For others searching and future reference, we have a long running f/s thread (link below) on the parts board for the optional OE 71-72 small block oil filler extension tubes and matching GM NOS tube to valve cover grommets. Mel


http://67-72chevytrucks.com/vboard/s...d.php?t=818966

.

[k29349]

Originally Posted by geezer#99

It might help if you explain the difference between normal and 4x4 grommets.
Is there a difference?
Could save someone getting the wrong ones.

I was also wondering why there would be a difference.

[Accelo]

I am not sure of this but maybe the non-for wheel drive had the a oil fill plugs in the valve cover and didn't include the extended tube?
Only speculation. Someone here know the answer.

[DeadheadNM]

The extended SB oil fill tube isn’t specific to 4wds. I believe it’s on AC equipped SBs and power brake equipped trucks. The NOS power brake unit I used for my Blazer had the oil fill tube in the kit.

[tj1970cst]

Originally Posted by HeloCrewChief

No offense but, I thought I already helped quite a bit. Just pulled 3, 14 hour shifts so this is about all I’m good for! Pretty obvious the differences between 2wd and 4wd engine compartments. Anyway, still hope this helps someone.

My personal best is 14 16hr shifts never more than 8hrs off. Hit all three shifts before it was done.

[HeloCrewChief]

Originally Posted by tj1970cst

My personal best is 14 16hr shifts never more than 8hrs off. Hit all three shifts before it was done.

That’s cute…you have no idea which makes me laugh.

[Rich72C10]

Originally Posted by Accelo

I am not sure of this but maybe the non-for wheel drive had the a oil fill plugs in the valve cover and didn't include the extended tube?
Only speculation. Someone here know the answer.

Originally Posted by DeadheadNM

The extended SB oil fill tube isn’t specific to 4wds. I believe it’s on AC equipped SBs and power brake equipped trucks. The NOS power brake unit I used for my Blazer had the oil fill tube in the kit.

I wished mine had the extended oil fill tube, it is a little bit of a pain to put oil in (2 Wheel 72 350, AC, Power brakes). I thought about adding it but I image the grommet wouldn't properly seal as my cover is for a cap.

My truck seems to have been very original and of all the things to go missing, why would the cover be replaced for a cap version (I assume extended oil fill tube covers have a different hole for the grommet and not a cap). Then again, no telling what has happen to the truck over its lifetime!

[DeadheadNM]

The extension uses the same OE cap labeled "oil" that's in place on the valve cover. After engine assembly this cap was painted orange with the rest of the motor. When the extension was used this orange cap was reused atop the extension. Here's an example on a 50k mi 72 350 pulled from a K20 Suburban for use on my K20: http://67-72chevytrucks.com/vboard/s...56&postcount=3

[Rich72C10]

1st, sorry for hijacking this thread and 2nd, sorry if I am being stupid. I am very interested in this oil fill tube. I almost bought a setup but then decided not to because I assumed it would not work with the hole.

Here is a photo where my twist cap goes into. The hole is notched, so the cap twists/locks. I assumed if I tried a oil riser tube, the required grommet couldn't seal because of the notches/lip in the valve cover?

Thoughts @DeadheadNM or am I over thinking this hole?

[geunther]

Originally Posted by Rich72C10

Here is a photo where my twist cap goes into.
?

Is that maybe a newer than 72 valve cover or something specific to 4x4? My originals do not have the notching, just clean holes.

[Rich72C10]

Could be but it is what came with the truck when I got it. Though when the engine was rebuilt the guys where 95% sure it was factory and had never been opened up. But that doesn't rule out the covers being replaced in its lifespan.

[geunther]

I think the grommets are used with a different hole design.

[Rich72C10]

yep, agreed or that makes the most sense to me!