8 3/4 goes boom

Big tires, 2900lbs, 800hp. You need a Dana. I'd also check the housing to see if it is bent. The tubes bend on them too.
To finish the season maybe try a set of pro gears. Not any long-term solution but they might help for the short term. I would not expect to get a full season out of any 8 3/4 given the setup.