Holley Spark Plug Wire Set 561-100 | Hooker continues to push the boundaries of performance with the new Blackheart line of performance exhaust systems for popular late model vehicles. The Blackheart line is truly a platform designed full exhaust program. From the cylinder head flange to the tailpipe, the Blackheart line is engineered to provide maximum exhaust velocity, ground clearance, style, performance, and quality!