Most of the early V8 fords had 8" rears, the 9" that came in them stock wasn't great either, it had small axle bearings, 28 spline axles, etc.
The 8" is decent, I knew of someone running one in a valiant and it worked fine, if you're putting out any power run a 3.70 or taller gear, 4.10's and 4.62's have a really small pinion gear and it will snap off the stem if you abuse it.