Can anyone ID these GM 8.5 inch gears for me?

[rastaz]

These gears came out of a GM 8.5 inch diff. They are 3.42's and were attached to an Auburn 30 spline posi. Looks like the pinion gear has a speedo gear on it? Does anyone know what car these would have come out of?

 

[novaderrik]

that's a reluctor wheel for ABS- i'd guess early 90's "bubble" Caprice 9C1 or pickup with antilock brakes.