Nick - Here’s one of my “Go-To” resources when it comes to parts info searching on the web.
GM PartswikiIt’s a searchable database that has numerous (but no where near all) GM Master Parts Books.
When I have a casting# to start with, I just enter that in the “Query String” box and click search.
The results, if found in any of the database sources, will display with a thumbnail of the parts book/books, along with a thumbnail of the page in the book(s) that you can click. The page will display full size so you can locate the item searched.
You can also do searches, using the GM Part#, name of the part, parts group number and even refine by the GM brand, type of vehicle and year using the lower drop down lists.
It takes a bit to sometimes hit on the correct part description, but as you try different things, you’ll learn what gives the best search results.
I can offer more tips and tricks later, when I’m not trying to type on my little phone screen.
