Generally, engine tuning is to modify the torque characteristic of engine by changing cam duration timing and height of the cam lift, so as to gain maximum torque and horsepower. However, when tuning the engine strictly, it should be carried out with the idea of securing effective area of the valve not only by duration timing and height of the cam lift, but also by through improvement of its intake efficiency. High valve lift allows huge amount of air to flow in, yet it mechanically damages the system and gains friction loss. Also, wide cam duration will deliver great power at high RPM, but it gives rough engine character at low RPM too. The engineers at Tomei have worked to create an ideal well-balanced profile of camshaft and succeeded to give it 1.3 to 1.5 times more effective area than regular camshafts. Tomei Procams are designed for serious professional performance use for high power and torque applications. Procams do require additional valve train upgrades and an programmable aftermarket ECU to configure the correct new engine management setup. Each camshaft is coated through a process that produces 0.5mm to 15 micromillimeter thin manganese phosphate coating on camshaft lobe and journal surface to prevent direct contact with metal valvetrain components while maintaining smooth operation. Installation Note: Upgrading the valve springs is required when using camshafts with cam lift greater than 11.0mm (not included.) When using camshafts with cam lift greater than 11.0mm on the intake side there is a chance that the valves can come into contact with the piston when the eVTC advances the timing. In this case it is highly recommended to recess the pistons to guarantee adequate clearance. Example: The standard advance amount with the stock head and stock pistons with the eVTC will require approximately 1mm valve recess on the piston. Procam Features: Linear Power Curve High HP and TQ Gains Will Require Aftermarket Springs Great Increase in Peak Powerband Larger Lift and Duration Than Poncam Camshaft Profile: VQ35DE Non-Revup (EARLY -05.01) Option A - (TA301A-NS04A) Duration - 258° Intake Lift - 10.20mm Exhaust Lift - 10.20mm Option B - (TA301A-NS04B) Duration - 274° Intake Lift - 11.30mm Exhaust Lift - 11.00mm Option C - (TA301A-NS04C) Duration - 282° Intake Lift - 11.30mm Exhaust Lift - 11.00mm VQ35DE RevUp (LATE 07.01) Option A - (TA301A-NS04D) Duration - 266° Intake Lift - 10.80mm Exhaust Lift - 10.80mm Option B - (TA301A-NS04E) Duration - 274° Intake Lift - 11.30mm Exhaust Lift - 11.00mm Option C - (TA301A-NS04F) Duration - 280° Intake Lift - 11.30mm Exhaust Lift - 11.00mm VQ35HR  Option A - (TA301A-NS03A) Duration - 266° Intake Lift - 10.80mm Exhaust Lift - 10.80mm Option B - (TA301A-NS03B) Duration - 274° Intake Lift - 11.30mm Exhaust Lift - 11.00mm Option C - (TA301A-NS03C) Duration - 282° Intake Lift - 11.30mm Exhaust Lift - 11.00mm Purchase includes both Intake AND Exhaust camshafts! Fits: 2003-2006 Nissan 350Z 2003-2006 Infiniti G35 Sedan 2003-2007 Infiniti G35 Coupe 2003-2008 Infiniti FX35+ Many more RWD VQ35DE applications! PLEASE NOTE Upgrading the Valve Springs is required when using Camshafts with Cam Lift greater than 11.0mm (sold separately). When using Camshafts with Cam lift greater than 11.0mm on the intake side there is a chance that the valves can come into contact with the piston when the eVTC advances the timing. In this case it is highly recommended to recess the pistons to guarantee adequate clearance. Example: The standard advance amount with the stock head and stock pistons with the eVTC will require approximately 1mm valve recess on the piston.