Years ago when I was young and green I was working in a truck shop, the shop foreman told me to "take that truck out and park it in the back yard". It was an old 70's Kenworth cabover with a really long deck and a Hiab mounted at the rear of the deck, it had a 6-71 Detroit in it. It was different from the regular cabover. It did not have a sleeper and was very bare bones, the only upholstery was the seat.
I parked it in the lineup in the back yard and when I turned the key off the engine did not stop, I looked for a tee handle on the dash and floor, it did not have one. It had a Road Ranger transmission so I put in high range and top gear and dumped the clutch and stalled it. With the long frame I could feel the cab twist until the engine stalled then the engine restarted backwards and twisted the truck the other way. It had a rear window and I could see blue smoke coming out of the air filter. It kept twisting back and fourth until I pushed the clutch back in with it running in the right direction.
There was a chrome button on the corner of the instrument panel, I pushed it and the engine shut off.
I still wonder if I left it running twisting back and fourth if it would still be running or would the frame have failed from metal fatigue.