Factory ratios offered include but are not limited to:

2.26:1 - Used in many civilian M-bodies over the years
2.76:1 - Used in 80s Dakotas
2.93:1
3.21:1 - Used in 90s Dakotas
3.23:1 - Used in many Slant 6 cars from 1963-1969, and 80s Dakotas
3.55:1 - Used in 80s Dakotas
3.90:1 - Used in 90s Dakotas
3.91:1 - Used in 67 Formula S Barracudas with power-lock
4.11:1

Aftermarket gear ratios available include but are not limited to:

2.26:1
2.76:1
2.94:1
3.21:1
3.23:1
3.55:1
3.90:1
4.10:1
4.11:1

source: http://www.dippy.org/forum2/index.php/topic,73.0.html