This would only be starting with the 2020 3500HD models.
Previous years the 2500HD, 3500HD, and the 3500HD DRW chassis, frame, etc on GM pickups 2500's thru 3500's were basically the same with very suttle changes which depended on the model built. The 3 OEM builds from the 2500 thru the 3500HD were mostlyjust bolt or purchasable enhansements which added to the truck's capcity, like higher capacity tires or 2 more added, higher capcity shocks, added spring capacity mosty on the rear, and had different badging. Rear axle diameter was the same on all 3 models but the 3500's had an and added cap on top of the rear axle housing on a some year's 3500 models. The rear end/ ring gear etc size was accoring the the selected engine size or type or 2DW or 4wd etc put in the selected truck. So many variations and options were available so can't really cover all the possibilities one could select from in the various size and model level combinations possible as it varied with year.