Re: Oil Leak?
I can't comment specifically about your engine (I'm use to the 5.0 litre engines as well), but logic tells you this:
If you can smell burning oil through the vents, oil is definitely leaking externally, and getting on something hot enough to burn off (like an exhaust manifold). The fumes then get picked up by the blower motor & vent system. For most engines, I'd suspect valve cover gaskets first. But don't rule out simple things like sensors (such as oil pressure sensor) that screw into the block.