First some data that is not documented:

The free spring length of the slider spring is 120 mm

The guide tube in the slide piston has a diameter of 12.67 mm
The dimension of the guide in the chamber cover is slightly larger
If excessive play is detected here, the chamber cover must be replaced, as this leads to considerable wear of the slide piston and the carburettor housing.

The height of the float chamber on the 914 is 35 mm.
If you suspect that the float chamber on a 914 is warped due to the float chamber nut being overtightened, you can measure the height of the float chamber in the hole for the nut. With the new float chambers with the long guide pins, you have to shim something in the middle.

The carburetors originally came from a BMW of the model series R 75/6
The designation of the 3 different carburetor types is basically 64/32/