GSC Power-Division billet S1 camshafts for the USDM STi and WRX with Intake only AVCS. These will not drop any low end power, and will create more power and torque across the entire RPM range. Good for stock frame upgraded turbos or up to 500 WHP upgrades. Upgraded valve springs arerequired; 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 may need to be filed down slightly for clearance - Please check during install
Proper break in and running high zinc oil is a must on flat tappet engines