Gears
 

have a 03 silverado 1500hd 4x4 and looking to change gears for more torque and towing power any suggestions or good set up.. Have 6" lift with 35's

First I would look in the glove box and get the code to see what gears I currently have. Here is a list of what's what...
Rear Axle Ratio
GQ1 -- AXLE REAR, STD RATIO
GT4 -- AXLE REAR, 3.73 RATIO
GT5 -- AXLE REAR, 4.10 RATIO
GU4 -- AXLE REAR, 3.08 RATIO
GU5 -- AXLE REAR, 3.23 RATIO
GU6 -- AXLE REAR, 3.42 RATIO
G80 -- AXLE REAR, LIMITED SLIP (POSITRACTION)
HC4 -- AXLE REAR, 4.56 RATIO
I would imagine with 35's you would probably want a set of 4.10's.

thanks appreciate it