Review on Lisle 36880 Dual Overhead Lock by Jeremy Byard

This came in handy when working with an Aveo dual cam timing belt, there is a spring loaded valve on the intake cam when the marks match and it wants to rotating the cam a few degrees in the wrong direction when trying to engage the belt, causing play between gears. This tool locks the cams and provides proper engine timing. You can do without it, but it simplifies the work and justifies its price. Fits multiple engines, see Lisle catalog for applications to ensure it fits you.