Where are you planning to mount the motor? Directly replacing the engine, adapted to the original transmission?(HPEVS AC51)
I'm not sure where you would put this single box. If the motor is in the stock engine location, or the stock transmission location, there will still be a shaft from the transmission or motor to the rear axle. Wouldn't that force the battery to be placed in at least two boxes, one each side of the shaft (and maybe one more under the hood or behind the rear axle)?Generation 1 Leaf Batteries
All in one single box on the back of the pickup
If you are planning to put the battery box on top of the pickup bed floor, that would work... but it seems like a shame to waste all of the functional space when there is so much volume under the bed floor to be used.