You need to use this valuable website to locate part numbers, etc....you will find links to many available on line manuals and I thank Keith Hardy for making this available:
http://chevy.oldcarmanualproject.com/Another valuable resource is
www.gmpartswiki.com - If you have a part number this will help you find out what its used on. It takes some time to do the research, but its a very valuable tool. PM me if you have any questions and I'll try to help if I can.