8 3/4 489 case snubber bolt size conundrum

Usually means the Center section came out of a truck. Kim
I'm snubbed..It was so densely packed full of dirt 3/4 full that I thought they never tapped it all the way at the factory. It felt like metal. Even when I hammered a small nail into it that didn't work. I had to soak it in oil for days then finally it gave way. Just dirt and the threads just needed to be re tapped. It took long enough though but I'm no expert.
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