Gearbox adapter. CNC technology made of ultra-durable 2017a duralumin, then hand finished. High precision and fit guaranteed. Engine: GM LS7 / LS3 / LS1. Gearbox: BMW M57N. Gearbox adapter. then hand finished. High precision and fit guaranteed. Engine: GM LS7 / LS3 / LS1 Gearbox: BMW M57N