I can completely relate to this, when I put my 360 together on the stand, I was very careful and meticulous about it, making sure that I did everything right. Only to find out when I put it in it had a coolant leak, I forgot to tighten the bottom bolts on the right side of the timing cover. After getting that fixed, the harmomic balancer was grinding on the bottom of the water pump. Then after the initial start up and cam break in, I had to tear into it a third time when I realized that I had misaligned the timing chain. The fourth time was to replace the passenger side head due to a bad valve seat. Then I finally got the intake manifold that had been in covid jail for 18 months, and swapped it out.
Last weekend I was putting in the defroster hoses, plus a new heater control cable and fan switch, and attempting to repair the turn signal switch cam. When I connected the battery to test everything, I found that the po had left some bare wiring inside the steering column, which quickly shorted out and fried a bit of the wiring harness for good measure.
Now I have to get another column, since the same po welded a large nut on the shaft of this one for a quick release steering wheel. I swear it never ******* ends.