Are you saying the exit for the oil hole at the back of the valley is that little hole by the oil pan in your picture?

I did a thorough cleaning up top and the valley was covered in oil after fifteen miles.

This led to identigying a fast leak coming from my HPOP line to the passenger head. Apparently I didn't tighten the o-ring boss fitting enough when I reinstalled it.

So now I'm back to cleaning the engine again.

 

Yes, this is where stuff from the valley comes out.

 

Sounds like you found it! That will leak plenty.

At the back of the valley on the passenger side is a hole that allows oil leaks from anywhere on top to drain down the back of the block. Usually misinterpreted as a rear main seal leak.

 

Well done!

This exact leak caused me a bit of frustration as I chased it for quite a while.

Link: https://www.ford-trucks.com/forums/1...l#post19407445

I thought for sure my pedestal o-rings were leaking and bought an endoscope in order to look at the pedestal o-rings with the truck running. Turns out the HPOP fitting on the passenger head was 1/8 turn loose. The oil was running out of the fitting, down to the plenum upper ridge, toward the back of the engine and down to the drain via the rear most valley pocket. Elusive SOB...

A quick tighten of the fitting with a wrench and all has been good for 1.5 years.

The illustration below provides a good cutaway view of how the fitting seats. A few years prior to this leak occurring I installed new OEM HPOP lines and torqued them to listed specifications. It either shook itself loose a bit or was tight enough over the past years until one day it wasn't.