I have just put one of these on my '84 and thought I would comment on it:

http://www.gowesty.com/library_article.php?id=1201

It obviously side-steps the possible failure of those studs/holes in
the block by using the much meatier holes made for the power steering
unit.

Comes with more parts than shown to accomodate installation on engines
w/o a power steering pump (like mine).

The mounting holes in the bracket allow some wiggle-room so care must
be taken that the alternator (pulley) ends up in the same plane as the
crank pulley.

Biggest design concern I have is that the bracket only offers a rear
support (the original had support for the lower alternator mount both
front and rear.  This seems to put a lot of faith in that bolt which
now must carry the load held only by the threads at its far end.  Just
an ordinary 80mm bolt I think -- the kind I have bent from time to
time.

Other concern is that the lower bolt is held by threads tapped into
the (1/4 inch) metal of the bracket.  I would have preferred to have
seen a large nut welded on the bracket -- but I'm no engineer.

At first when I just eyeballed the bracket I saw the ear with the
threaded hole was not square with the plane of the crank.  Uh oh.  But
then I did a trial fit of the lower bolt and saw that the threaded
hole was just a bit crooked and thus the bolt ended up in the exact
position it needed to be.  Odd, but perhaps they make the bracket then
use a jig to bore the hole as needed.  I'm still not an engineer.

Have a 5000 mile trip planned fo next month and beyond -- I will, of
course, carry the old parts along just for luck.

In summary: the appears well made, solves the problem it is meant to,
time will tell if it is well-designed.

One question for those still reading -- what is the thinking on belt
tension?  On some of my old cars I keep the belt almost loose, but
those are low-demand units.  On the Westy I have always kept the belt
pretty tight (and yet can get a chirp out of it on hard acceleration
with electric load occuring).

The reason I ask:  If I could get away with a looser belt I would feel
better about this design.

Thanks!

Geo