I did measure EGTs when I got home from work before I shut the motor down. I had to do it twice because they dropped a bit over the course of checking them, but stabilized at the values below.
380s 380s
480s 480s
480s 480s
380s 480s
I redid the cold ones and a few warm ones a couple of times to make sure there wasn't a variable like engine fan affecting things, but those values were very consistent. I swapped O2s last night and will take a log tonight and will be watching decel. I'm expecting that to remain the same. Next will be swapping injectors bank to bank and noting where they were and where they're going to see if the injectors are to blame.