Yes but I mean, some 3.0 engines have continuous VVT on intake, not ON/OFF like 2.7.
That's what I was asking you about.
8 cyl forget about it.
Without a powertrain compatible ECU absolutely nothing will work and dash will be like a christmas tree.
If you have a 6HP19 in there, and you can manage to mate it to the engine, then that's even better than manual I think - it can be tuned, and it holds about 600nm.
It is also possible to fit a 6HP28 to the car, which holds 1200nm. I don't see any point to fit manual.
If the 3.0 ECU runs the engine (firing order and sensors give reasonable values? Or do you have errors for cam sensors?) then most likely that's the only way to go.
But honestly, if you can't even find KRKTE yourself I don't see how you are going to succeed at this. This will need a massive amount of code patches to make it work.