I just purchased a rear main seal from my local Car Quest store. Darn thing was $23! It's supposed to be a teflon seal. It comes with a tapered plastic retainer that looks like it holds the seal in shape. I'm not sure exactly how to install it. I have the old seal out, no problem, but this one doesn't look like the old one. The guy at the parts store told me to install it with the large part of the plastic retainer toward the engine. In fact, he told me to put the cover on first, then install the seal between the crank and the cover plate. This is a federal mogul seal by-the-way. Anybody know about these things?