My '96gt has 3.27's.
I know the Speed Cal from AM only shows conversions for ... 2.73's, 3.08's, and 3.27's.
I'm not sure what year 3.55's started showing up.
A real easy way to figure out your gears if the tag isn't there is ....
Jack up the rear tires, mark the bottom of tire, turn drive shaft (counting rotations) until tire makes 1 full turn.
With 3.27's the ds will turn 3 1/4 turns for 1 turn of the tire.