depends, measure your turnbuckles first and make sure you can use the Associated length ones. does the X-C use standard (AE) or long shank (Losi) ballcups?

this is closer to what i'm running on the B2...but I couldn't find 'em for the B2. I'm running these with standard shank black RPM ballcups (not the super duty ones)

http://www2.towerhobbies.com/cgi-bin...?&I=LXY759&P=7