my friend has a 05 lly. the truck is stock engine wise besides a 4" exaust. its got a 8" lift with 35 or 37s not to sure. but anyow with the engine being stock and if he just added a chip would he have to worry about his automatice tranny? if so what needs to be upgraded on the tranny. thanks

 

Get efilive and then a good trans kit from a vendor.

 

How many miles on it? depending on the health of the trans and the power over stock of the tunes will be the factor of it will work fine or kick into limp mode every time he mashes down the go pedal.