I got into a discussion some time ago about welding a rear-end on a street vehicle – It became clear that the guy I was discussing this with did not fully understand how a differential works. The video below was made in the 1930's or so and is the best explanation I have seen to date.
The guy I was talking with was a young hot rodder and had heard that welding the rear-end really helps a ride "hook-up", but that's all he knew. No one had explained why this would be a bad idea on the street, and once he understood what purpose the differential serves, he saw the light. My guess is that he'll someday be able to share this same knowledge with a fellow young hot rodder, and also do more research on his own and teach himself something, and that I can get behind.