Chat habill , hello kitty, IAG Performance Competition Series Transmission Bushing Kit For IAG Transmission Mounts. The Competition Series Engine Transmission Bushing Kit is designed specifically for IAG Subaru EJ transmission mounts. IAGs transmission mounts feature the ability to swap bushings for street or track use. The Competition Series kit includes (x4) 90A durometer bushings that are stiffer than our 75A Street Series Bushings. The 90A durometer bushings help to greatly reduce the movement of the transmission under hard acceleration. Due to the higher durometer, additional NVH (Noise Vibration Harshness) is perceivable through the interior.