LS Flywheel Locking Tool, Compatible with Chevy LS1 LS2 LS3 LS6 LSX Engine Flex Plate Locking Holding Tool Kit, for 4.8, 5.3, 5.7, 6.0, 6.2, 7.0 Automotive Engine (Black Steel). ESSENTIAL TOOL: Flexplate locking holder tool is a must have tool for removing and installing the harmonic balancer on your engine.