2015 Freightliner DD13 puzzling me!

Long time lurker, but first time posting. I've ran into a DD13 job that has me completely confused and a scratching my head feeling incompetent as all get out! Lol

I replaced a head on this 2015 Freightliner Cascadia DD13 (GHG14).... After swapping the head, we primed her using the Detroit tank tool, cranked her over but she wouldn't start. There's no codes on the computer and nothing else in this truck was touched other than swapping the head for a brand new one.

Things I've done:
- Triple checked timing was correct (done per the book with proper Detroit tools)
- Triple checked valve lashings are correct
- checked out cam sensor for any issues, nothing there and it's getting power
- put a new crank sensor in just in case because it looked a little corroded
- Checked out voltage to make sure we have enough voltage during cranking
- All parameters on the DieselLaptop appear good
- Injectors all programmed per usual, but the fuel is not getting delivered via the injectors for some reason (not pulsing assumingly) but the computer suggests the injectors are good/green.
- It runs absolutely prefect on little spritz of ether, but will not take off on its own once stopping the ether...

I am completely lost on this one and don't even know where to begin troubleshooting... Anyone have any good ideas or have an issue like this?