After I installed a high-power audio system in my 2000 Jimmy, its 100A alternator was no longer able to keep the battery properly charged, and I was having to top off the battery with my Schumacher battery charger every week or two. This got me searching for a stouter replacement alternator. There were none listed for my vehicle in Rock Auto's catalog (all were 100 or 105A), But some poking around for alternators in their catalog that were spec'd for other GM trucks of the same vintage turned up a 145A AC-Delco Gold as an option for a 2000 Tahoe V8. It's geometry and physical dimensions matched those of the OEM alternator right down to the pulley size, and it used exactly the same connectors. The only difference was that the Tahoe alternator didn't have the threaded boss on its rear face that my OEM alternator had. However, when I inspected mine, I saw that there was nothing attached there. It was unused in my application.

I decided to take a chance and ordered the Tahoe alternator. It fits perfectly and works great! For anyone needing an alternator upgrade, the AC-Delco part number is 335-1092. Here's a pic of the unit installed in my truck:

 

This is great. I've thought about doing such upgrade if the alternator ever died on me, but I only had general info on which ones would fit. Having a specific example to use is super useful.

 

Just make certain that the threaded boss on the back of your alternator isn't being used. I've read that some S10's use that boss to secure a sheetmetal bracket securing a couple hoses - maybe heater hoses? - away from the engine. Not sure which year(s) or engine(s). My Jimmy never had any hoses there, so there was never any bracket, but there is one depicted in a GM Tech Tip and and shown below.