With the cam and its thrust plate installed, the crankshaft comes next. It's a forged-steel, cross-drilled piece that provides the long 4-inch stroke. The geared ring on the rear of the crank is for engine timing. A crankshaft position sensor (CPS) tells the computer the exact position of the crank by counting the gear's teeth. There are 58 teeth on the gear (hence it's 58X name), but they are spaced for 60--one tooth for every degree of rotation. The two-tooth gap is what the CPS reads to know exactly where the crankshaft is on its rotation.