No... The are very likely other limiting factors, like the design of the front suspension itself. (not the shocks) If its on the sled you have in your profile, I doubt you actually have 14 inches of travel to start with.
Why and how are you trying to gain height? Are you talking ride height? You need to change both the front and rear at the same time to avoid killing the handling. Also, by increasing ride height, you are also increasing approach angle on the track. (aka, its now easier to get stuck!) Increasing ride height in the front only will just give you a sled that steers incredibly heavy.
1) 2004 Yamaha Warrior
2) 2006 Yamaha Nytro