I worked in parts forever and have recently seen some stores packing up all the old numbers and sending them to "the warehouse". Most box stores will only stock numbers that move at a certain rate.
That being said, Advance still has the 7127-3 (10si IIRC) both in standard format as well as single wire. I wuold have to say the Isuzu might be avalible in-house longer but the GM will outlive it specail order wise. It's the most common alt on the planet...or at least it was.
Due to "collector" value, I believe the Lucas unit will be around longer than the Isuzu (distant future), however; I wanted something that would be in-stock at local stores now. Given the fact the Lucas is so easy to work on (and parts from VB and Moss are cheap too), I'll just keep some spare-spares to patch up my unit while I await a lifetime replacement. Ol' boy was having trouble finding me another Lucas unit, so I was thinking about an Isuzu swap but staying the course at least for now.
For $55 I really can't complain about it. This is the second one I wore out, but it seems the brushes are the problem. $4 and a few minutes with a soldering iron is a small price to pay for keeping it going. The cool thing is, if you have another brush housing; you can keep a spare brush set and regulator loaded and ready to go in the trunk. You can swap them out in just a few minutes with a stubby phillips with it still on the car. The rectumfrier is the hardest thing to change and even that doesn't look too bad but can't be swapped roadside.
Looking back, I should have bought two alts and always have a spare on-hand while awaiting a lifetime swap-out.
I like my attic parts house. No waiting and I always get the right stuff.
That's why I sent you the heavy-duty version of the heat shield template. I wasn't just for now, but needed to last ~way~ into the future.
Ya never know when you're gonna need it.