Ferocity02 thank you for testing it. I am very surprised that the gauge didn't show any vac at idle and that exactly what we need. Our engines need a strong vac. Sounds like we need to use the manifold for outta boost vac. Still wonder if doing a 2 part system where in boost it pulls from the turbo inlet.

I agree, always use a check valve. bomba makes really nice ones.

 

i just have my drivers side valve cover ran to a vented catch can. its very simple and it works. a system set up to pull a vacuum on the crank case would be more involved, but it would be better.

 

anyone know what that threaded bung in the 4.8L valley cover is for?

 

Isn't that for the oil pressure sensor?

 

Yes, that is the oil sensor bung, there is a spot on the front to hook a vacuum line. Mine came with a red boot on it.

 

That is only on the LS6 valley cover. Stock truck engines don't have the pcv port on the front.