What vehicles came with a 2.5-3in pitch fan.

[joegreen]

I am going to install a severe duty fan clutch on my 78 k20. In order for the fan clutch to work properly there needs to be enough drag on the clutch. I am going to the junkyard to look for a fan with a 2.5 -3in pitch. I need to know what gm vehicles to look at that might have these steeper pitch fans. That way i dont wonder around the whole yard. My guess is that most cars are out of the question. Thanks.