I would check the top of the engine first. Look at the very back of the valve cover gasket with a mirror. This area is notorious for leaking down the block and into the main seal area. Check the back of the head around the head gasket area. You can see it by jacking the car up and looking up from the bottom of the transmission area. I have seen this are leak after the engine is hot and under load. Once all of those are sealed, if you still need to reseal the engine, you can replace with the rope type seal or the neoprene seal. If your block has the rope type seal, you may need to remove the pins that were used to keep the old seal in place before replacing with a neoprene seal. If you look at the previous post I made on rear main seal leaks in this forum, I had a lot of great replies that might help you.
