I can almost guarantee that your rear end gears are 2.73. Check for RPO code GU2 (on the sticker in your center console or rear locking compartment door). If you have code GU2, then you have 2.73s. I don't think any more rear end ratios were available for that car (except for the B4C and probably 1LE cars), but I could be wrong.
Are you looking to replace your stock ones? If so I have a good recommendation for a good ratio for 305 TBI cars (just like mine and yours).
1991 Chevy Camaro RS (Is it plum or purple?)
Engine: 305 TBI (L03)
Trans: TH700R4
Mods: Some
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