The Entire cable was replaced because the cable has 3 legs to it as an assemble.The cable begins at the battery
then connects to the engine block,then from the engine block to the frame. The third leg starts at the battery and is connected to the right inner fender.
The section that is shown, is the unprotected flat strap which starts at the engine block then connects to the frame.,by the looks of it, it is a copper strap.

 

Yeah I finally found a picture of the whole cable as an assembly - I’m not too familiar with the vans but I’m curious why GM opted for a bare strap in that location - the pickups of the same year don’t have the bare strap as part of the assembly.

There’s also typically straps all over connecting the chassis, power train and frame. It makes me think those other straps are missing or damaged if the primary strap was the reason for the problem.

I’ll usually replace them with a length of 10 gauge if they need it. I’m sure it has to do with cost, but I’ve never understood or cared for using bare wire in locations where it’s sure to corrode.

 

That strap is a pretty common failure issue but as you said usually causes a no start. There's a video on youtube a garage guy shows how he found this same issue on one of these vans and fixed it.