Hey parts vendors, how about INCLUDING A DECENT SET OF INSTRUCTIONS in with the products you sell?

Kern Dog said
By this logic, the installation of the A/C system here from Vintage air should be different in EVERY 68 Plymouth simply because it isn't worth the time for the vendor to write decent instructions?
No. If the kit has parts that are common to all their kits and the parts are to be assembled to a production car, they can make detailed instructions that actually help.
To just leave it up to interpretation for every installation is piss poor business.
In 2019 when I was installing the Classic Auto Air in my Charger, I looked at other 68-70 B bodies at car shows and gatherings. There was a pathetic variance in appearance, placement of lines, parts and hoses in the cars that I saw.
Yes, there are ham fisted dipshits with false confidence that can fumble and figure out the job but that isn't the entire buying market.
These are not custom cars where every component is massaged and made specifically for this "one of one" car.
I'm talking aftermarket medium production parts designed to fit specific models.

How many kits do you think go into an exactly bone stock factory car of the same options package? I'd guess one did. What about if it had factory ac? What about various stereo or radio installs? Has it been converted from a slant to a V8? Does it have replacement sheetmetal anywhere? Are they running stock pullies? Is the windshield in or out? Doe sit have factory heater and fuel lines? Headers? Aftermarket ignition?

All of these things can have an unforseen impact. How many should the Mfg document? What pitfalls should they identify ahead of time? Be grateful a "kit" even exists. I bet guys with edsels wish there was a kit for them.. (I have no idea if there is, you get the point).

The Mopar market is already tiny compared to any other make. It's a tall order to ask a company to document all manner of known or unknown variations that might impact asy. How they might suggest to make the needed modifications might also not be how you want to do it.

Call them and ask, I bet they could explain it quicker than anyone could write it, and definitely quicker than trying to correct someone who has misread the manual already.