If the person leaves the VIN alone and makes the car what he wants it to be. Then there is not a problem. If you sell that car, then you need to make real sure the buyer knows that it is not what it appears. The clone cars are selling well now also. And they bring in a nice price. It will not be as high as an original R/T.or other rare models. We were looking at a 440 4-speed car on E-bay and could not believe the price that the car recieved. It was a total mess. NO engine, no trans and the rest of the car was rust and dead paint. It went for over $10,000. 20 bids. I could'nt believe it. So if you want a nice Challenger to enjoy, buy what you want. If its an investment, buyer beware. My 71 Challenger is an original 318 car. It now sports a 340 Auto. 727 with an 8 3/4 rear end. I'll be adding a Keisler 5-speed to it in the future. Does this hurt my chance to sell it. I don't think so, the upgrades have more than likely added to the value. I won't be selling it ant ways, I've had this car since 1978. I will be buried in this car. I'll run you to the resurection. I might need NO2. Ya'll take care and God bless. Randy.