05-06 5 speed 3.55
07+ 5 speed 3.31s

all s197 auots are 3.31

new edges were 3.27
[/quote]

Close... Only the 05-06 GT COUPE, 5 speed came with 3.55s. The 05-06 GT VERT, 5 speed came with the 3.31 just like the auto. The only way you could get the 3.55 in 05-06 was a GT, 5 speed, COUPE.
[/quote]

no, all 5 speeds came with 3.55s regardless of top, i dont know where this keeps coming from

 

Hello, I have a 2006 Mustang GT automatic. I recently installed a Vortech supercharger that came with the Predator tuner. I want to change gears from 3.31 to 3.73 but I don´t know if I need a new tune. The guys at Vortech said I do, the guys at Diablosport said the Predator tuner accomodates gear changes. The Predator does accomodate gear changes but is that all I need to do? Thank you.

 

always get a dyno tune after something big like that, and if you were to go with 4.10s in a centri you would be fine to just for the record, and add some LCA and you would have one awsome car