On my recent 440 build, I used the rear main seal and this set up from the FelPro gasket kit for the side seals. It consists of two pipe cleaners that you are supposed to dip in water. First, you fill the side cavities of the retainer with silicone, then push the wet pipe cleaners into the slot. It's supposed to cure the silicone since it requires moisture (never knew this). It sounded crazy to me, but I tried it anyway. I also siliconed around the outside of the seal where it meets the block and cap (I'm using a 440Source cap), and siliconed the cap to block mating surfaces. I have about 150 miles on it so far with not a drop of oil leaking.