Hi all. I’ve got a 69 f250 with 240 ci 6. Drove it back from the shop after some suspension work and noticed oil (?) leaking from the oil/breather cap for the first time ever. I wiped it off, but in the pics you can see where it ran down the valve cover. Any ideas?

 

Well, if the gasket for the breather is in good condition and the pcv valve and hoses are functioning properly, the only thing that would cause that is excessive crankcase blowby. It might have more than the pcv system can handle.