Not a big project but I fixed/upgraded my first part on the E-Revo! Replaced the spur gear with a metal one because I didn't want to shred a plastic one again. :
Amazon.com: 6Pcs Vgoohobby Hard Steel Front Rear CVD Drive Shaft Transmission Axle Upgrade Parts Compatible with Traxxas E-Revo 2.0 VXL 86086-4 1/10 RC Car (Blue) : Toys & Games