I bought several,12, Federal Mogul rear main seal kits with the newer grey side seals, I fill the main seal holder edges to the block up with clear adhesive silicone and let it dry overnight before using them. I force the silicone into the bottom edges to the block also with a small flat screwdriver that fits bewteen the crankshaft flange and the block. I'll try posting a picture of it, hopefully that will help