After getting those holes cut, I decided I'd take my chances and drill out the hole in the firewall for the wire pass through. I wanted to mount it a little lower, but lower and it would have interference inside, towards middle and it would hit map sensor, and other side had fuel pressure sensor and some difficult structure to work around.
No turning back now.
Pinned all the additional wires in the input/output harnesses for the holley and labeled them all.
Now i'll strip the rest of the loom off the original harness, lay these together and put it through the fiewall and start plugging it in so I can make the engine bay side all perfect length.
That's where she sits now.
William