When I tore down my donor truck's (1979 F250) 460, I thought the flexplate looked good enough that I might reuse it. Months later when I was cleaning parts I got lucky & found a problem it had before reassembly.
The old truck had been sitting several years before I got it but I got it running. Knew it had a vibration but wrong flywheel didn't cross my mind. I thought it was mostly original so wasn't suspecting part swapping to be the cause of the vibration. Trans turned out to have salvage yard writing on top of it which said 1981 400.
Just glad I caught it.