Howards Performance Single Racing Valve Springs w/ Damper - 1.265" O.D. - .875" I.D. Spark Plug Boot Sleeve Includes FP Pro Cal 4

Includes FP Pro Cal 4 Calibration Delivery Tool M-12655-F

Ignition Plug and Play with GM HEI

Thick foam layer provides superior dent protection

2006-2007 Mercury Grand Marquis

Howards Performance Single Racing Valve Springs w/ Damper - 1.265" O.D. - .875" I.D. Spark Plug Boot Sleeve Includes FP Pro Cal 4Engineered for racing use, springs are precisely coiled and undergo precision heat treating. Sold in sets of 16. The name Howards Cams has been synonymous with high performance camshafts since the 1950s. Howards Cams have always used on track experience to design the most powerful designs. This includes early Top Fuel favorites driven by Jack Chrisman and Larry Dixon Sr. Today we have even a greater group of experienced racers in Circle Track, Drag