I don't know too much about truck programers, I have an 08 Chevy Silverado z71 4x4 v8 5.3L. I put a RC 3.5 lift kit its more like a 2x spacers and a 2" block that goes under the leafs. I have 33x11.50 Maxxis Bighorns. I average around 11MPG. Im trying to improve mpg's when Im not using it for towing. Any suggestions for programers. I tried taking it to the dealership to see if they could reprogram the already built in computer to my tire size but they can't go any higher than factory size. Again any suggestions would greatly be appreciated.

 

Also my truck feels like its bouncing when I get around 40-45 MPH I've had the tires balanced and the alignment seems fine, it does not lean to one side or the other while I'm driving, any suggestions on that too?

 

As far as bouncing? A steering stabilizer may be what you need to help hold your steering straight going down the road. This would feel more like a shimmy though.

 

Well, my steering is fine, it does not lean to one side or the other, I can nearly see my truck bed moving up and down and you can definitely feel it in the cab.

 

bigger mud tires, go back and have them "roadforce balance" the tires. Generally puts them in check as far as ride goes. Mine did it at 40-50 and had them done with the roadforce machine and it rides really smooth now. As far as a programmer, don't get a programmer or a chip. Check out blackbearperformance.com or gowheatley.com. It will however void your warranty if you still have one however.