I know the number 153624 pretty well these days.
Back in school, I was changing the plugs on a motor. Put the leads back onto the plugs in the head, and went to start it up. It wouldn't kick over, so I pumped the throttle a bit. Just then, a nice big fireball full of half-burnt fuel burned my fringe off.. Yes. Turns out I got it wrong way around :roll:
At least the gasket failed right away, and not a few miles down the road!!