[ChevLoRay]

Best suggestion I have is to use some of the 3M Post-It tabs. They come in colors and you can write on them w/o any problems. They attach easily and can be removed if you don't want to have that tab on a specific page, anymore.

I know it ain't an index, but it's a help to know where something is when you pick up the book. Best I can tell, the pages have been placed in order in accordance with the time they were originally published. For me, the 1969 data starts with the Blazer pages, which detailed what was new and what changed. Having the ability to visualize your truck as you look at the pages, will be of benefit.