Originally Posted by Deviation
Am I missing something on compnine's web site? When I look at the diagrams, it shows a Chevy/GMC truck instead of the Envoy.
Compnine has some bad links on the graphics, yes. Sometimes you see a generic vehicle (often at the highest level), sometimes a pickup. 2-3% of the images are wrong as well, and all I can say is the site seems to be a work of love by a GM enthusiast who sells parts on the side, not a deep-pockets company who pays web designers a real salary.
And within the sections, you need to be careful if you're looking at one from the Chevy (X88) or GMC (Z88) or the other variants, and another code GM uses is ST155 for the SWB and ST158 for the LWB.