Could the leak be caused by crankcase pressure issues? I do have a PCV on one valve cover and a breather on the other so the crankcase is being vented. The only thing that I did (about 1000 miles ago) was to swap the locations of the PCV/breather (i.e. I moved the PCV from DS cover to PS cover and vice verse for the breather). I can't imagine that being an issue and creating the
oil leak.
I have also seen products where you put an additive in the
oil and it resolves main seal leaks. Blue Devil Rear Main Sealer. Bad idea? How does something like that work for the rear seal and not the front (since it isn't advertised for the front seal)?