So DTS was able to instal my 4.56 gear with no problems. The total cost was $715 and well worth it. Any of you guys in the detroit area should definately go to them to get this done. While rolling in first or second gear and mashing the gas I can give one hell of a smoke show. The truck seems so much more responsive and realy pins you back in the seat. Also, the speedometer re-calibrates itself so you don't have to worry about that. IMO this truck should have came with this set up straight from the factory it's a must have.