Changed the oil on my '96 Olds 3800 N/A this weekend, and I was a little concerned about some grit on the oil plug magnet... It'* hard to describe how much, maybe like this much: .... Enough to rub between your fingers.
The car has 132,000 miles on it, it maybe uses a quart in the 3000 miles between changes, there'* no knocking, no ticking, no start-up knocking or ticking...
It just gives me pause wondering if something is grinding away in the engine, like the timing chain or the mains....
Any thoughts?

Maybe you should get a flush of your oil to get the substance out of your engine.Make sure it is out . Then in 3000 miles check your oil and if you have shavings in your oil. I would think that your bearings might be going but I doubt it unless you just drive the thing into the ground. I had metal in my oil so I flushed it, I also took the pan off to look at the bearings and they looked fine. Mine is a 93 and it has just under 140k on it.