The cams and cam sprockets have an indexed flat built in so they only go on one way, but there is a slop fit to them so apparently you need to use a special tool or procedure to align them correctly before they get final torque down. I lucked out and made some shims so the cam gear fit snug on cam, and that 3.2 car I've been driving for 5 years and gets 28 mpg avg so it must be close to perfect to me.