Intake manifold oil fill neck cap

[1968 baby blue C10]

Can anyone tell me what the correct 710 cap is for the oil fill neck on a 4 barrel manifold and where I can get one? It had a push in cap when I got it and it slightly leaks occasionally.

[demian5]

That looks like a common oil fill cap you can get at your local auto parts store.

[1968 baby blue C10]

Originally Posted by demian5

That looks like a common oil fill cap you can get at your local auto parts store.

Really? It looks to me like it needs some type of twist in cap almost like a radiator cap. This is the factory caps that LMC has but none look right to me. Dang it picture went sideways .

[FirstOwner69]

I agree that you need a twist on cap. Probably the LMC # 30-4122. I'm no expert, but I don't recall that type of filler used in the intake after the 283s and 327s and implementation of PCV valves. Prior to PCVs that type of filler (but without the restriction and notches at the top) that I recall seeing used a push on ventilated cap similar to the LMC 43-4350-C. What year and displacement is the engine? Is the intake original to the engine? Does thit have a PCV valve?

EDIT: My original 350 with a hole in the valve cover uses a twist on cap. The diameter of the hole measures 1.20 inches (slightly greater than 1.50" at the notches). If that's what yours measures, I'd again say you should get one like the LMC 30-4122.

[demian5]

Its just a stant 10066 cap man...

https://www.oreillyauto.com/detail/b.../10066/5699121

[VetteVet]

I think the 307s still had that type. If so the valve covers wouldn't have the push in breathers like yours. IIRC

[100%Chevy]

My 68,327 has the LMC cap #1.
Mike.

[1968 baby blue C10]

Originally Posted by FirstOwner69

I agree that you need a twist on cap. Probably the LMC # 30-4122. I'm no expert, but I don't recall that type of filler used in the intake after the 283s and 327s and implementation of PCV valves. Prior to PCVs that type of filler (but without the restriction and notches at the top) that I recall seeing used a push on ventilated cap similar to the LMC 43-4350-C. What year and displacement is the engine? Is the intake original to the engine? Does thit have a PCV valve?

EDIT: My original 350 with a hole in the valve cover uses a twist on cap. The diameter of the hole measures 1.20 inches (slightly greater than 1.50" at the notches). If that's what yours measures, I'd again say you should get one like the LMC 30-4122.

Sorry I should've listed the specs, it is the original 68 307 but one of the previous owners added a 4 barrel, I don't know what from, I always assumed a later model 327. and it does have a PCV setup. So do you think the valve covers aren't original and the PCV and breather setup was added to it?

[1968 baby blue C10]

Originally Posted by 100%Chevy

My 68,327 has the LMC cap #1.
Mike.

I kind of figured that was the one it is but for some strange reason they have it listed as 250 and 292, weird.

[1968 baby blue C10]

Originally Posted by demian5

Its just a stant 10066 cap man...

https://www.oreillyauto.com/detail/b.../10066/5699121

Cool, now that I know I don't have to order one I can just get one locally and try it, thanks.

[1968 baby blue C10]

Originally Posted by VetteVet

I think the 307s still had that type. If so the valve covers wouldn't have the push in breathers like yours. IIRC

I checked in my 68 user manual and it lists a PCV and crank case breather. Maybe the oil fill neck is from an older vehicle? Of course it being painted and the manifold not being painted makes me think it’s the original oil fill neck.

[volksworld]

if that filler was original it would need to be one with a sealed twist-in cap like yours in order for the pcv system to be functional

[1968 baby blue C10]

Originally Posted by volksworld

if that filler was original it would need to be one with a sealed twist-in cap like yours in order for the pcv system to be functional

Wow I never even thought about that. I’m going to have to get a new cap soon.

[geezer#99]

Maybe you should remove the tube and plug the hole with a core plug.

https://www.google.com/search?tbm=is...HCcMCC0AUtcvM:

[1968 baby blue C10]

Originally Posted by geezer#99

Maybe you should remove the tube and plug the hole with a core plug.

https://www.google.com/search?tbm=is...HCcMCC0AUtcvM:

I would hate to do that, I really like the oil fill neck.

[3757chevy]

Napa #703-1692 Oil Filler Cap

[1968 baby blue C10]

Originally Posted by 3757chevy

Napa #703-1692 Oil Filler Cap

Thanks for the part number.