Nuke

Remember: you need to verify speed with a GPS. Using the speedometer reading may not get you where you need to go since the speedometer could be off due to the previous owner never resetting the PCM for a change in gears or a change in tire revs/mile. There are other ways to determine gear size by jacking the back end, spinning the tires 360 degrees and seeing how many times the driveshaft turns (or vice versa or something like that) but I've never done it.

loudnlow

Also 3:55 gears werent an option in 07 for an auto. It was an option for the 5spd though.