Here's a couple....
2nd Bronco brought home was a 69 with a 6 cyl that had been sitting in a pasture in Lousiana for 15 years..After getting the cylinders freed up, I put a set of points in, and robbed my gas can from my boat.....I never dreamed it would have fired up, but it did, but next thing I know, it dropped into gear and lurched forward, going thru my closed garage door, taking out my roll around tool box, the water heater, thewater softner, the back wall and my dryer.....
Installing a Holly Carb, and having great difficulties getting it set. Winter time, garage mostly closed, door to house open for heat, and not realizing the fumes had gathered in the ceiling....Backfire thru the carb, rolling up the hood, scorthing my eyebrows and moustach, then looking up and seeing the pretty blue swirls in the ceiling of the garage, the laundry room, living room......
Not using a torque wrench or locktight on my ring gears when intalling 4.11s Spectacular damage to my detroit and rear chunk.....wonder how much time I have on the front diff????
Fuel injection conversion.....9 months of gathering parts and info, 2 weekends of install, developed trouble a year later at roundup, could not pinpoint the issue, 1 week solid changing parts, ripping it all out to return to carb/HEI setup, only to find out the ECU relay had moisture in it....