I used a piece of #1 for the positive and two # 2 in the trunk for the grounds, I also use two or more #4 grounds to the frame from the engine as well as the aluminum elephant ears. You can never have to many grounds on a race car with the battery in the trunk
Ditto here too. Separate ground to the motor, pickup points on the body, steel is a poor conductor of electricity. Copper is much better
