Running a car safely and efficiently on electricity means more than just adding an electric power train.
Brakes. You want the best brakes you can get, due to the extra vehicle weight from the heavy battery pack. An EV will probably have power brakes that can be operated by an electric vacuum pump with a switch and reservoir. In a conversion, brakes can sometimes be upgraded by substituting parts from a different model vehicle. This might mean a heavier-duty pad and rotor system, or replacing drum brakes with rotors.
Tires. Tires will affect rolling resistance and amperage draw, impacting the EV’s economy and efficiency. Fat tires, extra big wheels, or extra small wheels will all cost extra amps—and dollars. Normal-size tires for your model vehicle, especially ones designated “fuel economy” tires, are best. Keep them well inflated, which generally means at the rated limit stamped on the tires. Low-rolling-resistance tires are available in some common sizes, to further decrease rolling friction.