Which performance tuner after regearing and bigger tires?

[Nicholas Alderson]

I'm hoping this is the right section...

 

I just regeared my 2011 GMC Sierra from 3.42 to 4.56, and the speedometer is wayyy off. At about 100kmph, it says 135-140kmph.

 

I'm installing a lift kit and putting 35'' tires on the truck next week and am looking at getting a performance tuner to fix the gearing/speedometer, and to adjust the tire size on the tuner.

 

The only tuner I know about is the BullyDog GT, but that seems like an over the top kind of tuner, since I don't exactly need it for anything other than to change the gear ratio and tire size.

 

 

I saw a thread that had mentioned the HyperTech brand, and found a "speedometer calibrator" tuner that they offer, but not sure how reliable they are.

 

Can anyone recommend me a different tuner that will allow me to change those settings?