Welcome to Just Commodores, a site specifically designed for all people who share the same passion as yourself.
Dude should have left that 6cyl diff in there so you could blow mofo' up first big burnout...on a private & properly supervised track
Are you keeping AC? As if not, a lot of people including myself (plan to anyway) pull the loom through the big 60mmish hole there. Apparently rare spares do a grommet that fits which I why its what I plan on doing.
For efi loom grommet can slice through it with sharp blade then move it etc...later on super glue sliced part back together & tape up again.