ss2nv

I've just started the teardown process on my 96 SS. I'm planning on an aluminum blocked 454+ ci LSX (probably RHS). I've unhooked the wiring harness from the engine/transmission/computer, but there is a small bundle that goes through the firewall on the passenger side, just behind where the computer mounts. I've started to cut apart the wire cover and try to see where those wires come from, but I'm not sure... Do I need to go under the dash and remove the bundle going through the firewall or do I need to split out those wires from the rest under the hood?
Anyone have any help as to how to proceed? Thanks.

Here is the progress so far: