I dont know the specs on the JR but I run a single Airtronics 94359z (200oz/.10@6volt) for steering and 94357z for gas/brake (125oz/.07@6volt) Opti drive is dead weight after you take reverse out
The FOC will include a blockoff plate for the receiver door
After you make those mods drive it you will not believe how much faster it will be,the lighter your truck gets the more responsive it becomes which sometimes means harder to drive
Try to stick with tires that mount on Revo wheels they are very light and improve acceleration.This is only a fraction of the possible Mods you can make,The best thing is to race and see what mods help or hurt
