1991 Ford Bronco Bolt on water pump is stripped

Hey man, I went to change my water pump the other day, got down to the very lat bolt within 30 minuted, I put my socket on there and started turning, I turned and turned and turned till finally I heard SNAP, it wasnt the bolt breaking but it I had turned so hard I broke my socket and it stripped the bolt out, since then I have bought 3 different sockets thats guarenteed to get a stripped bolt out and all of them have failed so far. I tried heating up around the threads with a little propane torch and that hasnt worked either. Man iv worked tryin to get this one bolt out for probbably 4 hours now and nothings worked, any ideas?