For what it's worth, the first time I raced my 97 Cobra, which is relatively stock, on drag radials, it took three runs to destroy the spider gears and twist both axles. In stock form, they're not bad but have limitations. A few upgrades and they'll live a very long maintenance free life.
In other instances, they seem fine for a long time with nothing. I had a friend with a low 10 second auto Mustang that ran on a completely stock 8.8 for seasons without issue. One day, I was watching him at the track and he launched, got a few feet and the driver side axles broke and spit what was left out and the tire and rim rolled about 15 foot away from the car.
A friend of mine had a 93 Cobra with a 5 speed in it. He broke one of the axles so bad it looked like a bear chewed the end off. It basically exploded the splines and about 6" of axle after that! It ran 10.30s though.
