I wonder if they are 12 mm 12 point like the 1/2 and 3/4 tons. I have a swivel impact socket just for those, and they arent coming out easy without heat. They use some crazy thread lock compound
Those would be on the flange companion on the output shaft on the t case. Those would be fine. It is thr small 5/16" or 8mm hex bolts on rear axle yoke I had issues with. Got them out and replaced