I have been neglecting to update, but the car works! After sorting out an issue with the throttle pedal signal, the car is up and running. The first few drives were just around the block because the car is not technically "registered" for street use. This is my first experience with a non-production electric car, but I can safely say the driving dynamics are vastly improved over the orginal. The motor makes no vibrations, so it is very smooth running down the road. The power is also greatly improved. The Hyper 9 motor makes roughly 120 hp and 170 ft/lbs of torque. It is not gratuitously fast like a Tesla, but certainly quicker than a stock spider. Because of the torque curve, you can start off in third gear, but 2nd seems to be the best combo for zipping around town. I have not ventured out on the freeway, but it pulls quickly to 60 mph.
The thing that takes most getting used to is the lack of sound and the clutch. The motor doesn't need to idle, so to pull away from a dead stop, you put it in gear and press the accelerator, no clutch slipping. You can also row through the gears and it behaves just like a gas engine. Out of habit, I always press the clutch when stopping, but there is no need in the electric car. The car makes a futuristic motor sound that is somewhat pleasant but no substitute for an Alfa engine. You can hear the gearbox and drivetrain noise, which fortunately is tame in this car. The downside to all of this is the 40 year-old car squeaks and rattles which now take center stage with no engine noise to mask it. Once you go above 45 mph, it's all wind noise.
All and all, I am happy with the performance. Next up, reassembling the interior...