P127C - 2016 Camaro with 2020 Escalade engine

A guy dropped a car off for me to tune (2016 Camaro SS) without telling me it had a different engine in it. I was under the impression it was the original LT1 with a cam...turns out, the entire long block is from a 2020 Escalade. Pump, rails, injectors, all of it. The only thing "LT1" on it is the front accessories and intake/TB.

This explains the long crank condition, P127C, and limp mode I've was fighting. I feel like I've read something or spoken with someone about how the fuel pressure sensors are not interchangeable or something along those lines...maybe the whole injector harness is pinned differently, I can't remember.

Does anyone know off the top of their heads if I just need to swap fuel rail sensors and injector data, or is there a lot more involved? Should i get all new LT1 stuff back in it (that's what i'd prefer)? Or should i just tell the guy to come get his pile off my property?

TIA

I would charge him double or tell him to come pick up his car. Yeah there are years you need to move a pin or use a harness adaptor if you're not using the LT1 fuel pump.