I recently had an oil leak that appears to be coming from the back passenger (right) side of the engine. I also had what appeared to be a power steering leak.

I sent it to the Steelership for diagnosis and they said the oil leak what the rear engine main seal. I have done some reading around and it seams that oil present in the bottom of the engine around the trans join could also be the cam chain tensioner seals.

Question is how do I tell between the two? From what I can see I dont have oil around the side of the valve cover near the air box but its difficult to see the back of the engine.

 

Pull out the air box, get yourself a flash light, eventually a mechanic's mirror, and have a look.
Folks would laugh at my idea, but I would say to get a seat cushion, set it over the manifold and hop on top of the engine (kneeled).
It is the best "seat in town" to see what's going on there, without pulling a hamstring as it may happen if you'd lean over the fender for too long.

From what I've seen in my 12V, if the rear cam seals or plugs leak, the oil pools in those "honeycomb-like" groves on the tranny body.
If the rear main seal leaks, you would have oil only on the bottom, or on the sides of the engine (potentially also on the edge of the tranny where it connects to the engine).
I may be wrong though...