The weights were updated on MC boats across the board, the way I understand it the boats are built using more fiberglass (especially resin) than engineering had figured so while the 197 didn't change the posted weights were a bit lower than the actual weights.
Technically the ILMOR engine weighs a bit more due to it's cast iron exhaust manifolds, the block itself if the same so no difference there block to block. The 6.0 liter does weigh more than the 5.7 and likely more than the 03' 6.0 (the 03' was an LQ block, in 07' this was swapped for a full cast LY block).
Not sure on the platform height, technically these two boats use different platform brackets but a 197 platform sits in the same spot on the hull across all years (at least as I recall).
Final difference would be the prop. I know swapping the prop on a 5.7 Liter TT has a pretty big effect on the wake.