battery and engine ground?

63dartman as long as you have a large cable like the one put on your car to the engine then you are fine. The problem I have seen in the past is guys put the large cable to the frame and rely on the small cable or mounts or throttle linkage, etc to make the high amperage connection when the starter motor is engaged. You can use the chassis as the large ground as long as you have a large cable attached to the motor.

Chuck