You have a 1970 Mustang 351C shaker base, number 70072. It should also have two holes on the mid plate for the front stud marked 2V and 4V.
I have the same shaker on my '70 Mach 1. It is still a valuable piece, I paid over 1,000 U.S. for my complete assembly, postage here to Aus was huge...
That Mustang tek article is wrong, the snorkel shown in the top pics is not for a Cleveland and the Torino base is a different height to the Mustang base. I believe the Torino Cleveland base is part number 70143.
These pictures show the correct snorkel for the Cleveland base, and the 2V and 4V holes on the mid plate. Which mid plate came on yours?