Congratulations on your new acquisition. I have heard that the 2Kd was the better motor when compared to the 1KD even though the 1KD has higher displacement and torque numbers. I would keep as much of the motors factory drivetrain as you could. The 2KD was likely only available with an auto transmission with few exceptions. The ECU will be trying to communicate with the transmission and if there is a different unit in it’s place the ECU might get confused.
You need to figure out a transfer case that will fit the transmission that the motor wants that also has the correct output for your 4runner.
You may need to change the gearing in your differentials because of the diesels low end torque.
Wiring is going to be a challenge because finding a wiring diagram is going to be difficult . Good luck!
