The Race Series Engine Trans Mount Bushing Kit is designed specifically for IAG Subaru EJ transmission mounts. IAG’s transmission mounts feature the ability to swap bushings for street or track use. The Race Series kit includes a 4 piece solid steel bushing set that is stiffer than our 90A Competition Series Bushings. The solid steel bushings greatly reduce the movement of the transmission under hard acceleration. Due to the solid steel structure of the bushings, NVH (Noise Vibration Harshness) is very perceivable through the interior.