Found this, to much for me, but

RaniDart70 said
its cobbled up with a lot of different parts. I guess survivor these days means wrong dash with a 75/6 cluster....a steering wheel that was not available in these cars. Changed out front seat. Supposed to be a 70 but has a 71+ side stripe. Don't you just love how the wiper motor was just spray bombed with the rest of the engine compartment. That engine looks like a late 60s 318. Definitely not the right color to be a "survivor" 70 340 and something is going on with the alternator.

all of these are really ok for a project ...cant expect much from a 45 year old car ....but to claim survivor status .......I think not.

some sellers either don't know what they have or they think the mopar crowd was born yesterday.

I think you are right, allot of people just don't really know what they have, and just assume by looking at some pics on the internet, that the car they are trying to flip looks like that Demon 340 car they saw on the internet, so this must be the same thing. I bet upon inspection, you will find on the casting on the block to say -318, the motors look the same, that's the only way to tell that I know of, to a more trained eye, like some of you guys here, know other details to look for. None the less, this could be a fun car to fix up and make a driver out of.
I try to give some sellers the benefit of the doubt, that they just really, don't know what they are selling.