8 1/4 rear end pros and cons

Certain year Dakota and Durango 4wds had 3.55 and 3.91 gears WITH Sure Grips! I pulled 2 from the local Self Serve yards and had them installed in 8 1/4 axles.
I ran an 8 1/4 in a 360 Dart and it performed great. I hammered the car and the axle held up fine. It is a beefy design that should be able to handle plenty. The killer to any setup isn't just horsepower, it is "shock loading". This is a condition where the driver imparts sudden loads to the axle. A 4,000 rpm slam into gear with slicks ? NOT good. A decent automatic on street tires? much safer.