Yesterday I was putting my 4.108 Perkins back together, and forgot to start the fittings for the oil jumper to the rocker arms. Oh yeah, torqued down the bolts, adjusted the valves and everything before I realized my mistake. I even got my wife to try and pry over the oil jumper so I would not have to redo what I did, but it was all for not.
Hanging my head in shame, I unbolted the rocker arms and started over. But of course in trying to get the fittings started, I galled the threads, so I had to machine out the rocker arm, and then retorque everything, and then set the valves again.
That was pretty dumb I admit.