The wooden blades are 315mm in length and come prefinished in the kit. The blades typically require balancing before fitting and flying. I would recommend just a straight forward check for Center of Gravity and adjustment as necessary plus making sure they are the same weight by adding tape at the center of gravity. Both my sets of blades were perfect for CG and close enough not to worry about on weight. This is unusual and most have had to balance their blades to avoid unnecessary vibration. In the above picture take special note of the brass bushings in the blade holes, be sure to put these in or you will almost definately throw a blade during flight.

The Trex 450X seems happiest at around 2400 rpm for headspeed which is the limit for the wooden blades supplied in the kit.