[A1971Blazer]

In my opinion they make a great upgrade from the V-belts.....there are the heavy bulky steel ones that are prone to cracking....most people stay away from those....then there are the aluminum ones that are more desirable.
IIRC you need the correct water pump because it turns the opposite direction from the old school pump
You can watch eBay...sometimes they come up for sake there fairly cheap...just make sure you get all the fasteners and braces as well as the brackets....
If you have AC...it will have a different style compressor as well.