The most stupid thing I did was in timing the 235 which was in the '48 when I bought it. I knew there was a hole in the bell housing which was used to time it. But did you realize there's a hole on the driver's side??? See picture.
I aimed the timing light at the driver side bell housing hole and adjusted the distributor to bring in a bolt hole in the flywheel. Yep, it ran. Not well but it ran!
Other less stupid things I've done again and again but the above was done only once.
34 Years. Now with a '61 261, 848 head, Rochester Monojet carb, SM420 4-speed, 4.10 rear, dual reservoir MC, Bendix up front, 235/85R16 tires, 12-volt w/alternator, electric wipers and a modern radio in the glove box.