GSC Power-Division Billet S1 camshafts for the 2008+ STI EJ257B With Dual AVCS. Good for stock turbo or up to 500WHP(GT35R) upgrades. Upgraded valve springs are required; Beehive valve springs are recommended but not required.
*Check Pictures for cam placement. Long nose= Left Side. Short nose = Right Side
**Due to the lobe size, head castings will need to be filled down slightly for clearance.