you can replace just the stepper motor if you want. There is a DIY for that on the forum. You can just swap the cluster, but you will need to have it programmed for the current mileage. Some places you can pull it out, send it in, and they will replace the stepper motor.
I'm sure you searched and know that if the truck has less then 80k miles gm will provide from assistance on gauge cluster replacement. Up to 70k parts and labor free. 70-80k free parts you pay 1 hour labor.