97-03 Grand Prix natural 3800s also use a 3.29 differential and 35/35 gearsUm..they are all 3.29 buddy. The driven gears are what change the FDR.
From TEPFinal drive-differential ratios
2.86:1 in standard differential only
3.05:1 in standard differential only
3.29:1 in standard differential and also the HD (Heavy Duty) and Volvo version differential
-Drive and Driven sprocket combinations and ratios
33 Drive / 37 Driven creates a 0.892:1 ratio
35 Drive / 35 Drive creates at 1.000:1 ratio
37 Drive / 33 Driven creates a 1.121:1 ratio
The Drive and Driven sprocket ratio will directly factor in to calculate the overall transmission ratio. For example most of the Supercharged 3800 powered vehicles come with a 3.29 HD differential but they have a 37/33 sprocket orientation and this will overdrive the transmission and create an overall ratio of 2.93:1