This is one of those cars that's crying out for a small block Chevy, and rear wheel drive.
I did a study once, back when I was on a GM project, t convert the GM EV-1 to a Chevy engine, rear wheel drive. Eliminating the batteries and replacing them with the Chevy drivetrain actually saved some weight. It could have been quite the halo car for GM, but that was a time when GM was running out of money and courage.
When I was young ad stupid, I replaced the 2 cylinder, 425 cc engine in my 2CV with an 1100cc, 4 cylinder engine from a Citroen Ami. Not too long afterward, I managed to twist the 2CV driveshaft right in half. The 2CV had inboard brakes, so most of the braking power was also lost.