Is a 7.25 rear strong enough?

It may have been on this forum where I read that what kills these units is extended one wheel peel burnouts. In this case, the spider gears are under great strain as opposed to two wheel burnouts where the spider gears are somewhat stationary.
Sure Grips for 7 1/4" axles are rare.
The Roadkill guys had a mid 70s A body project where they welded the differential and did a series of drag races with it. Eventually, it started making some bad noises.