Everyone dropped compression ratio... to lower chamber temps (and pressures) and thus lower NoX emissions. It certainly was not for better performance...
Had a 114 LSA Crane HE cam in my 315C.... Good economy while cranking out 325-350 HP. And would shock the AAA guys running the courtesy emission test in the mall parking lot by passing HC and CO emissions, but the 10.3 SCR made passing NoX a no-go.
