While Traxxas may have beefed up the Revo 2.0 suspension arms, they’re still not nearly as tough as RPM versions, nor are they as light. RPM A-arms weigh in 5 grams less than stock, per side, for a total weight loss of 10 grams! RPM geometry also has its advantages. Our angled leading and trailing edges not only cut through the air cleaner and more efficiently, those same edges allow the A-arms to slip up and over tall objects with less chance of a direct impact stopping you in your tracks! RPM front A-arms for the Traxxas Revo 2.0 are molded from our indestructible blend of engineering grade nylons and sold as one upper and one lower A-arm. All RPM A-arms are manufactured in the USA and carry with them a limited lifetime warranty against breakage. Technical Notes RPM #81462 & #81465 replace stock Traxxas #8631. RPM Revo 2.0 A-arms will not work with long travel (LT) style rockers. Upper A-arms will not work in the lower roll-center hinge pin hole. RPM A-arms have a deeper pivot ball hole than stock to prevent the pivot ball from bottoming out. to install the pivot ball correctly, thread the pivot ball into the A-arm until the pivot ball threads end exactly at the end of the A-arm. Do not bottom the pivot ball threads in the hole - you will stress the a-arms and void your RPM warranty. Upper A-arm Notes: RPM Upper Front A-arms were designed to utilize most of the adjustability options available on the Revo 2.0. However, do not run the Upper A-arm in the lower roll-center hinge pin hole. The A-arm will contact the outdrive of the axle. Final Adjustments: Once your new A-arms are properly mounted on your truck, take the time to use your RPM Camber Gauge (Part #70950) to accurately check your camber angles of each wheel. Proper camber angles vary according to personal preference (from 0° to -3°) but the front wheels should be identical to each other and the same holds true for the rear. Make only slight changes at a time to the upper and lower pivot balls and do not over thread them into the A-arms. Toe-In should also be checked after Camber has been set. It can be checked with an RPM Camber Gauge as well if it is placed against a flat surface (such as a 2" x 4" that will extend upwards to the center of the wheel) and the gauge is checked horizontally at the center of the wheel (0° to -1° of total toe-in is an accurate starting point for the front wheels and -2° to -3° for the rear wheels). Adjustments should be made at the turnbuckles.