Comp Cams 127650 4.6L / 5.4L 3V XFI SPR Stage 3 Blower Camshafts

The Comp Cams XFI SPR Stage 3 Blower Cams are designed for max effort, limited street applications. Built bottom end, ported Cylinder Heads and upgraded Intake Manifold are a must. Best if used with a large Centrifugal supercharger such as the Vortec JT or YSi, Procharger D1SC or F1X, or Paxton 2200. Shift points will be around 7200 RPM - 7500 depending on Intake Manifold used. 4.10 gears and 3400 - 3800 stall suggested. Custom tuning required. Upgraded Valve Springs and Phaser limiters required. We normally run lockouts with these camshafts and suggest an intake centerline of 109 when using lockouts.