As far as I know it is if you go by the addendum they out up on the Losi site. Follow it 100% and you should be in there. You also need to use the stock rubber gromets for the servo as it helps with the viberations and raises the servo up a little bit more. I have a good season on mine and have the same throttle servo in there from when I built the buggy. I run the stock radio tray with no extra bracing on the tray. I did add the rubber o-ring under the rec. batt. box about half way through the season. I set up the throttle throw at 60% gas and 45% brake on the EPA. That was the most I throw I could get without the servo trying to move the radio tray. Hope that helps.