Those 2003 LBY7 tunes are for a 2500 Sierra work truck. I loaded one into a 3500 dually (same ECU and OS) and it worked but popped EGR codes due to no EGR hardware.

Here's the 3500's stock cal,...

These three I pulled myself, all are stock.

All advertised as stock. I just downloaded them.

*** I have .bin for two of the .cal so far, but it bumps the forum's 1MB attachment limit. I also have .cal for the newer cars that exceed 4MB.

All advertised as stock. I did not pull or label these files personally.

All advertised as stock.