EXP and truck stuff

[@HemiChrysler]

Once the belt and timing is set, rotate the crankshaft through 720° (2 full rotations), then recheck the timing marks. The crankshaft rotates at twice the speed of the camshaft, hence 2 crankshaft rotations turn the camshaft 1 full rotation. This is good practice upon any engine, but critical for interference engines. Interference engines are typically, but not always, DOHC.