And all that said, which I agree with, but I owned a 65 Barracuda that originally had a 273 4 speed, followed by a hot 318 4 speed that I drove very hard, still had its original 3:23 gear open 7 1/4 when I sent it down the road.
I believe the single wheel smoke show wiped out more 7 1/4 spider gears that any other cause. Most 7 1/4"s I've seen broken were usually spider gear failure related. Gene