What is this Port for (Intake Manifold) PIC

[gmcbob]

So, what's this port for? It's in the middle of the intake, on both sides.

From my '78, 350.

I'm thinking it's for oil, but not sure. If so, I assume that it's pressurized at the same pressure reading of my oil pressure guage? I've got oil gathering on top of the intake, and I think this is where it is coming from. Thanks!

(Hopefully the Pic works)

Bob "gmcboc"

[Russell]

Nope, thats your exhaust crossover

Your heads allow some exhaust gas to pass through that crossover so you have something to heat up the automatic choke for your carburator. It is also used for EGR valves as well, when the EGR valve opens up, it allows some exhaust gas into the air / fuel mixture from that passage, reducing allowing you to run more timing, and improving emissions

Oil collecting on the top of the intake would likely be due to bad intake gaskets(likely the front or rear seals), bad valve cover gaskets, or possibly a bad distributer gasket

[bluex]

Or possibly coming through a few of the bolts. Put some silicone on the threads before you reinstall your bolts. Not sure how much oil your getting, but it could be coming from that, maybe even a bad PCV valve.

[gmcbob]

Well, I guess I learned something new

Thanks for the help guys. So I'll be re-setting the intake this weekend.

Here's a few pics of the problem.

Thanks again,

Bob "gmcbob"

[Russell]

I'd agree with bluex -- Thats oil seeping up your bolt threads... before you reinstall the bolts, run a tap down the holes to clean them up, and a tie down the bolts to clean the threads, then put some silicone down the hole / on the bolt before re-installing it to seal them up from leaking again, as well as making it less likely that the bolts will come loose / loose their torque

[gmcbob]

Sounds great, appreciate the advice. Sounds like that should take of it!

Bob "gmcbob"