And yet they worked just fine in the 71+ B-bodies with 383/727's, even though that combo would weigh more, have more horsepower, and have a crap load more torque than that Scamp.
The 8.25" is more than capable of handling a sub-300hp 318 like the one you described. Either yours was in poor repair to begin with, or you abused the crap out of it. You can break anything if you try hard enough.