1983 Buick Regal timing

I have an 1988 Regal, 2.8L V6 engine. With my car there's two notches at the base of the tensioner pully. Directly facing the notches is a single notch on the other part of the base. That single notch has to be directly in between the 2 notches opposite it. If the single notch is more to one notch or the other then he needs to change the drive belt. Thats the ribbed belt that the tensioner pully rotates on the passenger side of the engine. The belt goes around about 7 or 8 pulleys. Hope this helps. He will probably need a flash light to see the notches, even in the daylight.