pulled from XAT
5 speed
Gear Ratios - Manual Transmission
1st 3.321
2nd 1.902
3rd 1.308
4th 1.000
5th 0.759
Reverse 3.382
Final 4.083


6 speed
Gear Ratios
Manual Transmission
1st 3.626
2nd 2.200
3rd 1.541
4th 1.213
5th 1.000
6th 0.767
Reverse 3.437
Final 3.692

I dont remember how final drive factors in but it looks like the six speed would be slower anyway