New ball joint for early Datsun 1970 240Z and 68-70 510. This is the 11mm thread ball joint found on 1968 thru early 1970 240Z and 510's. The steering knuckle on these early cars is smaller so the later ball joint cannot be used. The later ball joint is a 14mm size. See part # 800-662 for the later 14mm size.