[T3] New Oil Leak

[Toadpipe]

I've developed an oil leak on the left side of the engine.  I've had 
ample time to watch it while fiddling with my idle and the oil seems to 
pool up on the sheet metal under the left pistons and drip from either 
side where it meets the engine case.  Seems to me this indicates that my 
rocker cover gasket is bad so I'm planning to replace both of them.  
However, it also occurs to me that I could be dead wrong, any other 
cause of the leak I should be on the look out for?

Toadpipe