Well I got all the interior outta the blazer to clean up the wiring behind the dash and insulate the firewall and floor as it got pretty toasty in there last summer after the LS swap haha. I've searched the horrible wiring diagrams, but cant seem to figure out what this box is that's attached to the back of the stock pcm. I'm assuming its something for the old 4.3, which if so, its hittin the garbage can.