In this video I show an easy way to verify LS engine ignition timing using average tools you already have at home! It's super important to verify your ignition timing when running an aftermarket ECU as it being off could cost you power, or even worse, a motor. This method is pretty accurate and takes the math portion out of trying to do it with a piston stop. If you are using a screwdriver be sure to remove the valve cover and loosen the intake and exhaust rockers for cylinder 1, as the valves can open and hit your screwdriver.