Stage 1 (266/266) Cams:
GSC Power-Division S1 camshafts for the USDM 04-07 STi. These will not drop any low end power, but actually cause faster spool of the turbo, creating more power and torque across the entire rpm range. Good for stock turbo or up to 500WHP(GT35R) upgrades. These cams require upgraded valve springs to keep everything safe at high rpm.
Stage 2 (272/272) Cams:
GSC Power-Division S2 camshafts for the USDM 04-07 STi. These cams are built to suite the high horsepower Subys. With a power range of 500WHP and up, you need some certain mods to utilize the true potential of the S2s. Built motor, with a built/ported head, and a good engine management system. Dual valve springs are recommended, but a upgraded single spring kit will do the job under 8000 rpm. **Due to the lob size, some head castings may need to be filled down slightly for clearance.