Jims Crankcase support block tool for Twin Cam B is an innovative tool designed to protect the left engine case while servicing the inner balancer bearings or performing other general engine work. These blocks attach to the outer side of the engine case underneath the balancer bearing pads surface. The blocks are made of aluminum and have an inserted Delrin pad that rest against the case to prevent marring. The blocks properly support the case, keeping it on a level plane when using a press for bearing service work. These tool blocks also keep the case level when using JIMS tool ZPN751085 to remove the balancer bearings without an arbor press. Comes complete with instruction sheet.