Does anyone know if I can change my open 3.07 diff to a 3.46 LSD and stay in the Street Prepared class? I know I can change it to a 3.07 LSD but I believe you aren't allowed to change the gear ratio unless that gear ratio is available in another version of the car. Since other E46's have 3.46 ratios does this count and mean I can use a 3.46 LSD?