One piece axles and sealed bearings

One piece axles have this arrangement:

I think the street durability issue is more with using "Green Bearings", which I believe is a roller bearing, these days they use tapered bearings, which should be more durable.

The only way not to is if the bearing is a roller bearing or ball bearing and sealed.
The pic shows a "bearing assembly" indicating one piece, so not tapered. 
Most cars with one piece axles, such as Ford or GM use a ball bearing, etc. - which is fine because they'll take side-loading.
That axle looks a lot like what Ford and others use - and those aren't tapered bearings - tapered is like a front wheel bearing.

So basically using this setup it's being converted to a style like the big three used instead of the tapered bearing that AMC used. 
(AMC axles used tapered bearings and that requires a means of setting play because tapered bearings are two piece. )

(Not sure what you mean by "green bearing" - if you mean the seal, well, that could be reddish, black or green, even on ball bearings as I have ball bearings at home that have each of those color seals. For example, the sealed alternator ball bearings in my drawers have an assortment of seal colors, depending on year, maker, etc. - most are black, but some are green or reddish brown, too.)

Its not the best picture but top axle is a moser axle and the bearing that comes with it, referred to as a green bearing. I just worked on a set of the cut to fit axles and they came with the same bearing. I have seen an older set of moser axles in a car I was working on that had set 9 bearings in it. But I dont know if the shaft diameters are the same. I have been told that the green bearings do not handle the side loads of auto cross as well as the tapered bearings, but are ok for street use.