GSC Power-Division Billet S2 camshafts for the Subaru EJ207 version 7 and above with single AVCS. These cams are built to suit higher horsepower engine builds with a power range of 500 WHP and above. Certain modifications are recommended to utilize the true potential of the S2's including an upgraded engine block, built/ported heads, and dyno engine tuning. Upgraded valve springs are required. Due to the added lift and duration, cylinder head clearancing may be required.