Death of a /6

I've had terrible luck with s/sixes;
I traded a clean '67 Belvedere 2dr h/t for a less clean '63 Dart GT. The valves were loose and when I tightened them, I could hear the rod knock.
I had a '71 Valiant 198 that kept tightening the valves up and always ran crappy. You could actually see the valve retainers bouncing off the head.
I Have a '61 Lancer hyperpak (All missing) that started a little lifter tick that got louder until I realized it was the rods. Having no place to pull over, I put my foot in it until it went bang. I then pushed in the 'N' button and coasted off. the rod beam had broken at the crank and pin and thrown through the block and pan and wrapped around the block flange. The oil pump pickup fell off.
I have a '61 Dart (Big body) thad had #6 out. I got it running after being junked in '76, tried to drive it out of the pasture and threw #1 and #5 in the process.
We'll see how long the '68 Valiant lasts.....