Yes, do it. What's your entire engine worth to you?
This includes a link to Maine Sail's excellent article, as well as to one I wrote back in 1999, when I had the bracket replacement ON MY BOAT, as yet uninstalled, and the old bracket broke!
Alignment is critical.
So is getting the correct pivot bolt and arm bolts for your alternator.
http://c34.org/bbs/index.php/topic,7917.0.html
In my case, I did NOT have to remove the entire manifold, plus my studs were short but still long enough to hold the new bracket.
If you don't have to remove the manifold, it's a rather simple task.
I helped a good friend do his on his M25 on his E32. We had to remove the old studs on his, they were too short, but MS's article explains how to do that. URBAN MYTH: many say that you have to take off the manifold if you have to remove the old studs. Not true.
HERE'S ANOTHER REASON TO DO THIS:
I have a good friend with an M25XP. He neglected his raw water pump and it leaked all over his engine. He had to replace his oil pan. He also just learned his timing gear cover is shot, rusted though. Now here's the part that oughta interest you: they don't make these engines anymore. The timing belt cover is no longer available.
They are difficult, if not impossible to find.
So, WHEN, not if, your alternator bracket fails catastrophically because it is a casting, and it RUINS your timing cover, you will have $7,000 to $12,000 to spend on a new engine.
All because it was too "tedious" to do four hours of work for a $200 replacement bracket.
Why people ask...
But, you and another Ericson owner have figured: "It's been working so far, why bother?"
Yeah, right...
Why ask?
For the past 25 years many, many skippers have been URGING other skippers to DO THIS.
We're not doing it 'cuz we feel better that you DON'T.
C'mon...
Please excuse me for my exuberance about this issue, but we have seen altogether too many skippers who have lost their entire engines because they didn't know about this issue. Now we're "exposed" to one who KNOWS it exists and is asking whether he should do it.
NAHHH, why bother???