All of the other 450's still have steel arms, and steel axles. On the Ds you are going to be replacing the lighter aluminum parts with heavier parts. It's not going to be the heaviest, but not going to be the lightest anymore.
And what does that matter that will only come into effect for the Mx guys.
07 Blue Raptor 700
Yoshimura Rs-7
Pro Design Pro Flow w/ K&N
Airbox Eliminated
11:1 JE Piston
Hotcams S2
Dynojet PowerCommander III
(Front) 21" Holeshot Xcr's
(Back) 19" Mxr4's
Itp C-Series Wheels
Blue Tusk Nerfs
15t Front Sprocket
Comin Soon- Elkas