Somethings the site does that I don't agree

Are you really basing your argument on the fact that the Mecum listing is wrong? That's pretty weak.

They use various descriptions when describing the installed engine. Some like "a factory P-code 400 or a factory H-code 383" indicates correct style (maybe year) correct displacement Non-numbers matching. Others like "340ci V8" mean just that. All listings that have matching numbers are stated as such.