There are differences. Most carburetors were based on patent, either applied for or granted, and none of the manufacturers wanted to pay patent rights so they developed their own designs for the most part. A person has to do a fair bit of research on the different Model T carburetors in order to research the individual types to see all the differences.
When Ford didn't own a patent on an accessory that they wanted to use, he would give the company a big subcontract to manufacture for him but it also included the express licence to manufacture them in house if the subcontractor had material or labor problems that could impede Ford's manufacturing of their final products. Henry had agreements with all of his subcontractors or he wouldn't give them that big fat contract to begin with. He learned to do this after dealing with the Dodge brothers until he bought out their shares.