I think that I screwed up the installation of the rear main seal on my new 350. Is there any special thing I have to do with it to make it leak free? Do I silicone it? At Auto Zone they sold 3 different ones. I just picked one and used it. I think it's leaking. What a pain in the you know what. How hard is it to remove the oil pan with the engine in my 69 Elky? Thanks.