I have a 72 with 3 screw SU's and they have the long and short arms in the float bowl lids. Long in front carb, short in rear. I intend to set the floats on my bench top by setting the lid with its float and gasket on top of a small clear drinking glass with a 23mm scribe mark at the correct spot. Can anyone tell me whether the distance between the inside of the float bowl lid and the top of the gas is 23mm for both the front and the rear carbs on a 1972, or is the front 23mm and the rear so