I've had lunchbox lockers before. They actually work very well, but they're noisy and harsh. If the cross pin diameter is the same between the 8.2 and the 8" or 8.4", the carrier internal width, and the spline count matches, it'd probably work, but there's just not much info available anywhere on the 8.2 dimensions. I've tried to find info online on whether a 4.10 gear set from the 8.4 could be machined to fit the 8.2, but have not found any side by side comparisons with other diffs.
If I found one at a junk yard I'd buy it just to tear it apart and see what's compatible between the various 8" third members, but they're basically nonexistent so far in any cheap source.