OT: Many years ago, my brother came to visit (I was in southern tier/finger lakes NY, he lived in GA). Our project was to change the timing belt on my K-car. We carefully set TDC and took the necessary bits apart; we bumped the crankshaft accidentally but put it back (so we thought) using the timing mark. When we put it back together, it would not start, and my brother could see fuel blowing up out of the carburetor while I noticed that the tailpipe was pulling a vacuum; my brother suggested we move the carburetor to the tailpipe.
We went inside for Christmas dinner, which I ate without washing my hands as I was so depressed. I just sat there staring at the floor, and finally the light bulb went on: there were two timing marks; the reason was that way it does not matter to which spark plug cable you hooked a timing light.