Whenever there is money to be made there will be fraud. I frequent a local recycler (junkyard) and it is loaded with the C4C vehicles. I have pulled the fuel injectors out of a few of them and the residual gas smelled like it was a few years old. Obviously, the motors could not have been running when brought in. One truck had a rats nest in the air cleaner. There was one truck with a 454 in it. The valve covers and the intake manifold had been removed. The valve stems and rockers looked clean and there was no residue of the sodium silicate in the valley, only an oil film. If you find a low mileage motor pull the oil pan and check for anything other than oil. If it's clean, you got a deal.