I beleive as long as they are not pitted; you should be able to use them. Just make sure you use a good small wire brush and clean ALL the rust off real good and use some heavy moly paste when you install them. I once bought a set with the intention of putting them in that day so I cleaned them in a solvent tank; got sidetracked and never did!
About 18 months later I found them on the work bench; remembered what they fit and put both sets in a buddys cj,after cleaning them well and setting them up as close to perfect as you can get, they now have approx. 45k on them turning locked diffs w/35 inch tires and not a problem yet. Just make sure there are no pits in the contact surfaces.
think ? just how you do season a engine block pre machining and building it? YOU burrey it for a year or better and let it rust up real good! seems to make castiron denser?
use your better judgement,if their pitted after cleaning that you can feel with a fingernail they are trash.
good luck... gas.

 

1. The light surface rust shouldn't be a problem...
2. But then did you look at the bearings?
3. Light surface rust on them will cause a disaster.

 

Well Yeah...!!!!!!!!!!!!!!!!!!!!!!!! crunch snap boom!.!.!

13ftlbs.on axle ubolts????????huh!