I am rebuilding my 350 sbc engine, and when I took the block to the machine shop, I thought I remembered a seal or gasket around the outside edge of where the oil filter adapter bolts on. I called the machine shop about it, but he said that a 2 piece rear main block does not have a gasket for the oil filter adapter, it bolts metal to metal. I also went to the local chevy dealer, (lost cause) and they could not find a gasket or seal for it either. Can anyone confirm if the machine shop is right?