Hi,
Oil Pan leaks come to mind, also. I used a felpro silicone gasket when I changed the rear seal on my car(I used the lip seal, by the way).Anyway, a couple of thousand miles down the road, a leak started that at first I thought was the seal again. Now I think I have an oil pan gasket leak, right above the starter on the passenger's side. I would advise using the thick cork gasket that a lot of people sell. Kirban is one of those folks.
Front seals are equally prone to leakage,rope doesn't cut it in my book.Try the lip seal up there too. Yeah, you have to watch for those valve cover and intake end seal leaks too. All this stuff dries out with time, and the gaskets they have for today's motors do a better job, but our engines were designed long ago, when sealing tech wasn't what it is today. Plugging the leaks should not be an ongoing thing. Good luck!