Basically, the modifications are to the engines, structure, and avionics:

• Composite rotor blades.
• A composite after body.
• Upgraded transmission, capable of handling 3,400shp, up from 2,860shp.
• A new 3000 shp engine.
• Active defense systems.
• Synthetic vision for the crew helmets.

Not clear on the need for the engine upgrade, as the two existing 1,900shp T701D engines already put out more horsepower than the upgraded transmission could handle.