EK 630SHB-Z The Chain for H-D Top Fuelers. Pingel Enterprise, Inc. and EK spent two years researching and developing the world's strongest drive chain. With an unsurpassed 30,000-lb. tensile strength, the 630SHB-Z is specifically designed to handle the brutal horsepower of today’s V-twin top fuelers. Two pins per link. To order, specify number of pins needed (must be an even number). Master link sold separately.