The heart of the G8 GXP is the 6.2L LS3 small-block V-8, currently rated at 402 horsepower (300 kW)* and 402 lb.-ft. of torque (546 Nm)* pending final SAE certification. This engine is the newest member of GM's small-block V-8 family. It features a revised, larger-bore cylinder block, high-flow, L92-style cylinder heads; larger-diameter pistons; unique camshaft and camshaft timing; revised valvetrain with offset intake rocker arms; high-flow intake manifold; and high-flow fuel injectors.
"quoted from autoblog New york auto show pontiac g8 gxp"
Ls3 = non SC ls9, think this will be the engine in the z28 and perhaps a supercharger in the SS?