Help! 1969 GMC 250 CID, what’s leaking on my valve cover.

[BuilderBee]

I recently inherited my Dads 69 GMC Stepside, motor runs great! I’m a newbie at this so I apologize in advance for my inexperience. At the rear of the valve cover there is a hose and coming from the top, leaks oil. What’s does this do? Is this an EGR valve? Appreciate your input and advice. Where do I find replacement parts?
Thanks!

['68OrangeSunshine]

That's your PCV valve.
Positive Crankcase Ventilation.
The other end should go into your carburetor somewhere. It's a one-way valve. If vaporized oil is bypassing it, the valve is stuck. Replace the PCV valve and maybe the grommet, and you should notice an improvement.

Unlike prior model years, when vaporized oil was let out from a vent on top of the engine, in 1967 GM was nudged by the Federal Gov't to make those vapors get recycled into the carburretor to get burned with fuel/air during ignition.

On my '68 292 L6 -- which is much like yours -- fresh air is sucked into the crankcase thru the Air Cleaner and oil vapors are sucked out thru the PCV Valve at the rear, and funneled into the carbureter to be burned.

I no longer run a Monojet, but the principle remains the same.
The fatter hose forward goes into the side of the valve cover. A filter in the air cleaner screens the air to the snorkel under it. The rear hose comes out of the PCV valve at the back of the valve cover and into the Carb.
I usually replace the PCV once a year, just before Emissions testing.
They are easily available at any auto parts store.

[Steeveedee]

Yup, PCV valve. The hose on the valve cover where the oil fill cap is goes to the bottom of the air cleaner housing for filtered air. It probably has a spark arrestor screen on it, inside the perimeter of the air filter. The valve could be clogged, or the engine could have a lot of blow-by, which is combusted fuel and air leaking past the rings. That's easy to check. Just remove the oil fill cap and see if smoke comes out. You can verify if the PCV valve is clogged by pulling it from the valve cover and putting thumb on it. If engine speed doesn't change it's clogged, or potentially the hose is collapsed.

[BuilderBee]

Thank you @steeveedee and @68OrangeSunshine for your prompt response and I appreciate your help! 🍻.

[yuccales]

More pics of your rig are a necessity!

[Steeveedee]

Originally Posted by yuccales

more pics of your rig are a necessity!

yup!

[cericd]

Originally Posted by '68OrangeSunshine

On my '68 292 L6... I usually replace the PCV once a year, just before Emissions testing.

Dang! In AZ they do emissions testing on 1968 vehicles?

['68OrangeSunshine]

Originally Posted by cericd

Dang! In AZ they do emissions testing on 1968 vehicles?

Uh-huh. Any vehicle 1967 model year or later.
The L6 292 in my '68 C/10 Stepside usually passes, but I have a set of leaner Edelbrock metering rods and jets to put in the 1404 carb and try for a second pass if it doesn't.
The 350 V8 in my '71 GMC Jimmy was even worse, being looked at as a Hotrod Badboy. I got around that by getting it registered as a vintage vehicle with a Yellow [69/72] Year-Of-Manufacture 1971 AZ plate and collector car insurance.. Now it's emissions-exempt and I can register it for 2 or 5 years at a time. I went with 2 years...
My '67 K/10 Suburban with a 454 BBC was a beast to get thru emissions. Now I have a White [66/68] AZ plate for it standing by, if I can ever ressurrect it.

[BuilderBee]

Here you go. Exterior Photos

[BuilderBee]

More motor pics

['68OrangeSunshine]

Long bed Stepside. Way cool. Those are rare. Keep that rear step bumper. It's a good anvil.
What's the Odometer reading, Bee?

[yuccales]

That's a good old truck! I agree, keep that back bumper.

[BuilderBee]

It’s actually a short bed and needs some good ol TLC on the body and bed. I’m thinking of just buying the steel panels from LMC Truck online to save on labor work just to make repairs on rusted panels. Cheaper to buy the panels then have the truck painted.

As far as the bed is concerned I’m leaning towards replacing the wood slats with a synthetic lumber like Trex.

['68OrangeSunshine]

The Wide Angle lens shots threw me off.