Spun bearings, why???

Awhile ago I rebuilt the 3.8 in my '93 after the headgaskets blew. Put in a mild cam, some roller rockers, etc. The crank was turned 10/10. After driving it less than 4000 miles, I have a rod knock. I pulled the engine this weekend, dropped the pan and pulled the crank. I had 2 spun bearings and most of the ones that didn't spin are showing way too much copper. I measured each journal 2x at 90* apart to check for out of round. All measurements shown below are from front to rear, not in cylinder order:

Mains:
2.508/2.505
2.505/2.506
2.506/2.506
2.506/2.507

Rods:
2.296/2.296
2.297/2.297 **
2.297/2.298
2.298/2.299
2.297/2.297
2.297/2.297 **

The bearings that spun were for cylinders 4 and 6 as marked by the asterisks above.

Minimum specs for the crank mains and rods are 2.5190 and 2.3103, respectively. Taking these minimum specs and subtracting my average measurement makes the mains .0130 under and the rods .0123 under. This would certainly be expected since my crank was turned 10/10 as I stated.

Now, the question is, why did I spin 2 bearings?

Bueller? Bueller?

holy shit man, I just read a different language.

Yeah dude wrong questions for this forum. This seems to be mostly a beginners and moderate car people. But hey someone might know.

I kinda figured. I've posted on tccoa and on another board. I should have the rest of the engine torn apart and to the machine shop in the next couple of days.