What makes an HO an HO?

If what was left was a majority, or 50.1%, could you call it an HO. On it's face, there is NO evidence other than PHS that states it's an HO...and that, it's only the engine...there are specific part numbers that made an HO an HO...carb #, manifolds and distributor...to a lesser extent, radiator.

If a car is called "F" and "F" has a special package that is called "X". "X" consists of special parts A, B, C, D, E, F, G and H...and is missing A-H. Intents and clarification, .A-H are drive train parts. If a person can not tell from the exterior appearance the difference between a 400 and a 400 HO and missing all the parts, is it an HO?

Lets say an HO package consisted of more than just manifolds, cam, carb, distributor.fan..The HO shares roughly mid 90% of the same part numbers,including the block, heads, intake as any 400. The block is the exact same as any other 400 block, nothing special. same as the heads, intake, alternator, water pump...nothing special.

Part numbers that are HO specific?

Fan, exhaust manifolds..carb..to a lesser, UQ radiator..

It is not a 4 bolt block, same block casting, material content and manufacture as any other 400 block.
It is not a different manifold as any other 400
It is not a different transmission (shared with any other 400)
It is not have different heads than any 400
Same distributor as any other 400

So is an HO an HO based on born with or "paper" documentation if all said parts saying it's an HO are missing? Is it an HO if the missing parts are replaced with non originals? Or is it only an HO if it retains it's number correct VIN and EUN stamped engine, and VIN stamped trans?

What makes an HO an HO?

My opinion is that if man creates a product for a specific purpose...or intent, and the purpose or intent is absent, relegating it to be the same or similar to any other, that the true intent of the product is now void. The product is now the same as any other. The specific intent of the HO was a step above a 400, albeit minimal, to a 400.

Assume PHS did not exist and Jim didn't have the microfiche. How would you be able to determine a 400, 400 HO or Ram Air apart if the original drive train was missing? Why do you think at one point there were more first gen Z/28 SS RS/SS Camaro's than were produced.

A debate is just that which was initially asked. My opinion was and will remain....this car, absent original or HO specific parts is only an HO on paper. To call it an HO is based on just that...paper.