as i understand it, a weber 32/ 36 is named such for the diameters of the two barrels. what are hitachi carbs? and espesially, what is the size of the carter weber 1 barrel?

EA81 C/W 1bbl = 36.5mm

 

The 3 digit number in the model name of Hitachi carbs gives the throttle bores. The first two digits are the larger bore, and the third digit is the last digit of the smaller bore. You have to use common sense to fill in the missing digit for the smaller bore.

 

EA81 Hitachi carbs all have "306" in the name, thus 30mm & 26mm.

EA82 Hitachi carbs all have "328" in the name, thus 32mm & 28mm.

 

There are some Nissan or Isuzu trucks that used Hitachi carbs with "340" in the name, and are thus 34mm & 30mm. I looked at one of these in a junkyard once, and they have the proper mounting pattern to fit on a EA82 intake. The one I was looking at was not computer controlled either, and had very little emissions junk on it since it was on an older truck.