OutbackJoe

Greetings, Im reaching out to the Subie community for some help. I just completed a head gasket job and i am working on final re-assembly. I thought i did a decent job on the repairs and putting things back where they need to go, but alas, i have two ground wires (i think) i failed to label. One is a black wire coming out of the firewall in front of the drivers side and the other is a hefty black and yellow wire coming out of the wiring harness that connect to my battery (see photos 2/3). I believe they both attach to the intake manifold above cylinder 4 (upper right from bird eye of engine bay, see photo 4). However i also noticed another threaded hole on the block (photo 1) that is within reach of ground wire coming out of firewall. Does anyone know where these go?