If those are the Carter-Weber (Motorcraft 740) carbs used on the 1300cc Ford engines, Tom Langdon provided me information about 5 years ago on where to obtain different sized jets. I did not want to mess with the very well behave carburetors, so I never obtained the jets.

Maybe someone can confirm that 73405 is the C-W 32 DFT (Motorcraft 7400) jet part number? If it is, different jet sizes are available here.