On my way home from work a couple days ago I stopped to talk to a friend and when I was getting ready to leave he noticed some oil dripping on the ground under my truck. Approximately a couple tablespoons after sitting for just 5-10 minutes. I crawled underneath to look at it today after the weather broke, and it's leaking from what appears to be the head gasket. It's located about an inch above (and an inch forward of) the place where the vacuum pump oil feed line screws into the engine block. It's immediately below the injector pump, IIRC. I'm not a good mechanic, but isn't that where the head mates to the engine block? The truck has 309,xxx miles.
Pretty bummed right now, cuz I can only imagine what this will cost...

 

Can you take a pic of the leak, it sounds kind of low on the block to me. Do you have any coolant in your oil or oil in your coolant? Head gasket replacement is pretty straight forward on our cummins, nothing like fords or chevys.

 

If it's below the injection pump, it's not the headgasket.

 

Upon further checking, it's apparently the tappet cover that's leaking, from the information that I've found online. Good news for me, but still a bit of a job to fix.

 

and there is also a gasket between the powersteering pump and gear drive that causes an oily mess. the gasket kit is like 15.00.