The case of the mysterious carbs

Question:

Back in December 2013 you discussed SU carburetors, and the fact that you were familiar with them. I have inherited an SU dual carb setup that I know nothing about, and would like some help identifying its application. Since it has “JAPAN 220” stamped on the intake I have to assume it once was on a Japanese vehicle, i.e. a Datsun, maybe. I have attached a photo that may help. Thank you for any help you can give.

Answer:

I have rebuilt and tuned S.U. carbs, but I don’t know all the different applications in which they were employed. They go all the way back to World War I, and it seems like they were used on nearly every British car ever built at one time or another. Also, the Japanese early car industry relied extensively on British engineering and design partly because British cars fit their needs better than those from America.

The Japanese have knocked off the S.U. design over the years too with their own brand of Mikuni carbs some of which use the same technology. Do your carbs say S.U. on them anywhere? How about it Auto Restorer readers? Can you help Tom solve this mystery?