Here's a list I found with a quick Google:
RacersGuide.com
"If you need something for your stock car, you'll find it here!"
Ford 9 Inch Gear Ratios
Ratio Teeth
2.8 42-15
2.86 40-14
2.91 32-11
2.94 47-16
3.00 39-13
3.07 43-14
3.25 39-12
3.33 40-12
3.45 38-11
3.5 35-10
3.55 39-11
3.6 36-10
3.7 37-10
3.75 45-12
3.82 42-11
3.89 35-9
4.00 36-9
4.11 37-9
4.22 38-9
4.33 39-9
4.44 40-9
4.5 36-8
4.56 41-9
4.63 37-8
4.71 33-7
4.86 34-7
5.00 35-7
5.14 36-7
5.29 37-7
5.43 38-7
5.50 33-6
5.67 34-6
5.83 35-6
6.00 36-6
6.20 31-5
6.33 38-6
6.50 39-6
That's not a complete list, I have a 3.91 gearset myself, that was Ford built, has the oval logo on it. 3.0, 3.25, and 3.50 are the common factory ratios in the low 3's.