Michigan Motorsports LS7 Rocker Arm Upgrade Trunion Kit These LS Series retrofit trunion kits are designed to convert stock LS7 Series rocker arms into captured roller bearing rocker arms. The factory bearings are a known failure on the LS Engines. When they fail they send small bearings through the entire engine. The upgraded trunions use a captured roller bearing allowing for a reliable smooth rotation. The upgraded trunions also give more stability at higher RPM. We use these trunion kits in anything from stock 4.8's all they way up to 1,000+hp turbo motors. The stock factory LS rocker arms are very strong and very light. Once you upgrade the bearings and trunions the rocker arms handle similar to very expensive roller rocker arms (at a fraction of the cost). These are a must have for anyone installing a aftermarket Cam, Supercharger, Turbo or Nitrous. Kit is for LS7 engines only. See our other listings for other LS applications