when i was looking to buy my first kit, i wanted the biggest one, so naturally, i looked into the "80."
it only took me 2 or 3 websites to realize it wasn't really an 80. i got over it, and purchased the 66, 68.5, 60 whatever something...
the information is out there, easily accessable, and there's only been one or two dealers that i've seen that didn't have the true displacement in obvious view on their websites.
the explanation for the way the chinese measure displacement compared to the rest of the world made sense to me (the explanation, not the reason,) and i bought accordingly.
if people who haven't built one yet talk to me about my bike and ask me, i tell them it's an 80, but give them a quick explanation why it's really a 66. if it's someone who knows motorcycles and engines, i tell them it's a 66.
most people just want to know three things. how much it costs, how fast does it go, and if it's legal.
i lie about all three.