The official SAE certification is complete adn teh LS3 in teh GXP is rated at 415 hp and 415 lb-ft torque. Although still 15-20 less than what it puts out in a Corvette the anticipated 421 hp for this same engine rpojected (but not yet certified) in the Camaro was depressing to some. A G8 GXP will never beat a Camaro in a 1/4 mile, but 6 hp is easily explained by extra exhaust plumbing.
http://media.gm.com:8221/us/powertra...bination_n.pdf
SAE Certification on GXP
Linear Mode
