The matchbook cover is a minimum. Just set it in the center and be done with it.Anyone know the actual crank sensor air gap for a 91 SC? A match book cover is a rather vague dimension.....
I always put it on a little loose, rotate the crank around til the balacer plate is in between the sensor then adjust and tighten it. Then have someone turn the crank while watching to make sure you have clearance. A friend and a 2 ft breaker bar helps big time but I've done it by myself.