Check out this Dirt Bike Magazine GasGas EX450F build. You can view the full online story on Dirt Bike Magazine. Here is a closer look at the bike and the Magazine coverage.

Blue YZ250
Close up of FMF pipe
ProX Sprocket close up
Two men next to each other smiling (Jay on the Left, Keefer on the Left)
Two men next to each other smiling (Jay on the Left, Keefer on the Left)
Two men next to each other smiling (Jay on the Left, Keefer on the Left)
Two men next to each other smiling (Jay on the Left, Keefer on the Left)