This chart can help you pick the right two tranny gears to keep the speedometer right on the money when changing your Monte's rear gear ratio.
2.41 Rear Axle - Drive gear is A - Driven gear is N
2.56 Rear Axle - Drive gear is A - Driven gear is O
2.73 Rear Axle - Drive gear is B - Driven gear is Q
3.08 Rear Axle - Drive gear is B - Driven gear is P
3.73 Rear Axle - Drive gear is C - Driven gear is Q
Drive Gears:
A - 13 teeth - White - pt# 8634934
B - 12 teeth - Red - pt# 8634935
C - 10 teeth - Green - pt# 8639906
Driven Gears:
N - 26 teeth - Brown - pt# 25524922
O - 27 teeth - Black - pt# 25524923
P - 29 teeth - Green - pt# 25524924
Q - 30 teeth - Blue - pt# 25524925
Hope this helps clear this sometimes confusing issue up.