Damn good question. What did you source the PCM out of? I have factory manuals and schematics for both F-body and LS equipped trucks.
That's a whole lot easier to fix than a transmission issue. Phew!
(I had to look back through the thread... called it in Post #5
^^ PB Blaster seems to work well. I am also a fan of wicking candle wax into a stuck fastener utilizing a propane torch for heat.
In retrospect, I really do need some penetrating oil at the very least.