We're lining things up. The garbage sacks over the headers is a Hotrod Magazine trick that I read about 15 years ago. To ease the installation of headers during a engine rebuild, just lay them in the bay with covers over them as the engine is installed. I've read of a lot better tricks from Hotrod. I think it just made the job more difficult and beat-up the headers worse. Next time we do this job we'll skip the bags. Let's see, we'll be 83. No sweat.