Agreed- The 06 4.2's make 291hp stock, with a torque curve flatter than Florida. These engines are basically a large-displacement Ecotec, although they have different lineage (they do share valvetrain components). 300hp in Camaro-tune would be no sweat. But, as stated- they just wont fit without a bigger compromise than they are willing to make. Bummer.
Mine is going to make north of 850hp with a stock (mod'd) crank. There are Comp Elim guys running these with carbs making 550-600 N/A hp, spinng 8600-9Krpm.
But I'm biased...
