how to tell if 70 Dart is real 340

I had that washer welded on several cars that were not 340's. and all standard shift v-8's had the torque boxes that I had. You can put the numbers on any body. There is one thing that I had used to catch a clone and it worked twice. The exhaust hanger on the right side and even if itis there you still can catch um. Take out the rear seat. Lift the car and remove the factory right side rear muffler hanger. Then unbolt the dual exhast body support Some have three bolts some have four, Go back to the inside of the car and remove the screw or small bolt that holds the hanger stud plate in place. If it is painted underneath it more than likly a clone. These are applied to the body before paint. The one supposed "340 car" I looked at never even had the dimples drilled for the dual exhaust plate, they fasten the hanger right through the floor. This I found was the thing that most forget when they are making a clone. If the plate isn't under the seat its a fake. I went with a person to verify a bronze 1970 swinger in Pa., the car was pristine and all the numbers were there. This was being sold as a totally restored numbers matching 340 car. I didn't even have to take the seat out I just looked under the car and the factory 340 exhaust hanger mount was not there and never was the dimples were never drilled. This guy was giving all kinds of excuses why it wasn't there. Bottom line is my freind would have gotten burned. He did sell that car and I saw it in a magazine being portrayed as a numbers matching car. I have bought alot of cars in my days. All kinds of mopars. There is a lot of scumbags selling clones as originals , Beware E-body buyers e-bodies are the worst for this. Remember only real performance cars from 68 on had dual exhaust from the factory. The washer , the boxes, and the numbers can be added. not many remember the factory hanger mount. And if they do , they usually put it on over the factory paint behind the seat.