What's the difference? (if any)

 

Gm same thing unless your talking about old gm helm books. The old helms use to have a supplement that was used for part dissembling/ rebuilding components.
There are additional books for electrical only.

 

Thanks. I bought the shop manual plus electrical diagrams on CD. Wanted to make sure I got all the goods.

 

Should be complete and 8a should be a supplement.

 

The manuals like Haynes and Chilton that you can generally buy at auto parts stores are helpful but they only provide enough information for a non mechanic to be dangerous. A good manual is a proper dealer repair manual. They used to be year specific for a specific model. A single large manual to cover just 87 Camaros etc.

Now a days, everything is either online or on a DVD because of how much information is required so finding a proper manual can be difficult.

For the average person however, having a copy of the Haynes and Chilton manual for your vehicle should cover most of what you need to know. What isn't in one manual should be in the other but they won't have a lot of diagnostic information like what's included in a factory manual.

Even now, the Chilton Online probably has as much information as a dealer manual.