I believe this chevelle is an original Yenko chevelle
...documentation from Vince Emme
...with build sheet
....I saw the car when it was painted the non-original color ( red ) and the original motor and rear and transmission was out of the car.
....the present owner repainted the car within the last 4 to 6 months and installed the original motor and rear end and transmission ( which I believe may be the original also.)
...Check with the owner if you have questions...but it looks like a good investment.