Hooker Headers Super Comp Adjustable Drag Race Headers enable you to professionally tune primary tube and collector lengths to accommodate any track condition. These headers include extra long primaries as well as 12'' long slip-on collectors and other size and length slip-on collectors are easily interchanged for tuning! You can alter the relationship between the primary length, collector diameter and length to increase or decrease horsepower and torque levels. For a track that is "tractionally challenged" you can shorten the primaries or collectors as well as increase collector diameter to decrease low end torque. At tracks with excellent surface preparation the primaries and collectors can be lengthened or collector diameter reduced to increase torque for a harder launch. Super Comp Adjustable Headers have taken more championships than any other brand!