narrowing a b-body rear

Personally, I would stay away from the green bearings. Yes, they work. But the stock tapered bearings are a superior design, and adjusting them isn't nearly as hard as some people make it out to be.

X's 2.

Chances are the bearings you have are still good, clean and inspect them, if they move smoothly and don't appear to be loose, get a needle for your grease gun and fill em up.