This is the 2005-2008 LX 5.7 Automatic 3" 2 piece shaft designed for 1000HP. This shaft is a direct bolt in with custom billet plates to convert the rubber drives over to 1350 u-joints. we recently took delivery of a new balancer that can spin shafts up to 95000rpm (most balancers only spin from 400rpm-3000rpm) and what we have found is after 5000 RPM the slider in the middle becomes unstable. A slow speed machine will not see this problem or be able to correct it, we have had great success with fixing this problem by balancing the shaft at real speed so if your looking for a shaft as smooth as the stock one but strong enough to launch the car, look no further.