Tim,
Here is a directory of scans of pertinent pages from a GMC Master Parts Book:
misc GMC headliner scans NOTE: 1662 & 1663 are (I think) the model designations for Suburbans (end-gate & rear doors)
The information in section 23.3700 gives information similar to that found in the Chevrolet MPB.
However, there is an interesting diagram of a COE headliner on page 461. The front-to-back bars on one piece of headliner appears to be part of the headliner. If that is the case, there might not be separate part numbers for those metal reinforcing bars?
23.3680 is FASTENER - TOP LINING PANEL (FRONT AND REAR) and is used on 1662 & 1663 (I have no idea what this refers to - no diagram).
