Never like the CS style GM alternators, they usually have rear cooling issues and the diodes and voltage regulators usually get cooked.
When I worked in retail parts, I saw a tonne of these warranting out even the new ones from AC Delco. The rear housing was made to small and was poor cooling. The CS alternators for big rigs last longer, but they are bigger.
The older SI alternators are much more reliable, I like the 135amp from '85 Cadillac Fleetwood Brougham.
But there are way more reliable alternators from Nippon/Mitsubishi/Bosch for Hondas/Toyotas/Nissians they make 130amp ones for about $100 usd.