I have a 2100 that came on a '63 292 powered truck. The venturi size is 1.23, with mechanical choke. It is almost a sure thing the carburetor wasnt on the truck originally. There are almost no other ID markings. A 70 inside a circle cast into the side of the float chamber, and a BIG number ten on the bottom outside of the float chamber.
Any idea what the carbs original application was, and which rebuild kit should I order?

The drivers side front foot, there will be some numbers stamped into the foot there.
That will be the part number and can be easily decipered to tell you waht the original application was (is).

Ford built that 1.23 carb from 1963 thru 1968 though and since you have a manual choke would be surprised to find the original application was a truck.

These days those 1.23 are sought out for racing applications since that is the biggest venturi for the 2100. (OK, OK sure ford also made the 1.33 but those are as scarce as hens teeth).

Let us know the part number.

Bill White
White Automotive