Big lift with short duration focuses on building cylinder pressure on boosted applications. Requires BC spring/retainer kit. ECU and CNC cylinder head with oversize valves will deliver big gain in performance. Due to high lobe lift, it is mandatory that you change the valve guides and use BC valve seals. Failure to do so will result in retainer to guide contact causing damage to the head and/or cams. Must run with aftermarket pistons with proper valve reliefs built-in. Cannot be ran with stock/OE pistons due to possible piston to valve contact.