I'm trying to find out what years and models of blazer body parts are interchangeable on a 2003 blazer LS. I need to replace both quarter panels and hood. Thanks

 

You might try looking at a GM parts distributor to find the part numbers and then see if they are the same on other years. I've done that before for mechanical parts. Even when the original part from GM is no longer manufactured the part number is still available. It might be worth a try for body parts.

https://www.gmpartsxperts.com
https://www.gmpartsdirect.com/