I had been toying around with the idea of getting an old Fiero or Miata to be a donor car for an insanely fun EV conversion project, but shortly thereafter I was stricken with a horrible realization. If I put 10,000 dollars into a 900 dollar car, what happens if I total it? How do insurance companies handle cars without their stock powertrain? Can you insure a car for more than its Kelly Blue Book value? How have you worked around it all?
Ask your insurance agent. Nobody else can give you a reliable answer. Perhaps they'd let you insure the conversion parts separately. But the only way to find out is to call and ask.