It often depends on if you know the exact car number it came from. Otherwise, it could be off any other 351 Mach I.
Lansing- Thanks for the response. I was not aware they put top loaders in mach 1's. If it is a true shelby tranny, any guess as to its value? It is currently in a 71 mustang-says its from a 1969 gt350.
Ford top loaders are not unique to Shelbys. In 69 the toploader out of a 302 Ford Mustang will be the same as a Shelby. Ford made 2 different toploaders small input and big input, 1"3/16 and a 1"1/16 I think. The big inputs were for the 428s and 429s, and of course you could get a close ratio or a wide ratio. But there is no such thing as a Shelby toploader. Price will vary as condition varys. If you are selling it let me know what you want for it, I have a 69 Shelby GT350 and I am always looking for spare parts.