As I recall, there were two types of Cobras offered by Shelby. The first was the 289FIA (although other v8 engines were used) and it was the one using the Bristol body from England, had wire wheels and did not have a front scoop. Reproductions are available in both fg and aluminum and exhaust can be directed to the rear of the car. The second was the 427 version. With the more powerful engine, wire wheels could not be used, a scoop to funnel air to a large "turkey pan" that surrounded the carburetor and more muscular curves in the body around the wheels. t The exhaust is through side pipes. It also is available in both fg and aluminum.
Agree with above, cobracountry is a good source.