Rear oil leak in a 350 engine?

It depends on where the leak is. However, if it is leaking at the pan you need to replace the oil pan gasket and if you are going to do all that work it really isn't all that more to go and change the rear main seal on the back of the engine (and vice a versa). Warning this is a very labor intensive job compaired to the price of the parts. Also, having use of a lift and transmission jack make this job much easier. There is no way I would have done it without these items. It would be a knuckle buster trying to break these bolts loose while lying on your back with only a foot or two of clearance. Also, if you do this plan on a whole weekend job unless you are part of a NASCAR Pit Crew...and if you were you wouldn't have asked ...