Clymer manuals are pretty much the standard for after-market motorcycle repair manuals.It covers both general maintenance and more in depth mechanics. In any Clymer manual you will find detailed drawings, instructions on how to break down the engine, and so on. This one is no different.
The M340 Clymer Repair Manual covers the GL1000 engine from 1975 to 1979 and the GL1100 Standard & Interstate engines from 1980 to 1983.