Whatever the float height:
Remove bowls.
Invert carbs (thats upside-down to me & you

)
Take weight off floats until they are only just touching needle valve (by tang)
Now measure from underside of carb body (metal casing where float bowl mates with body) to top of float (as they sit with carbs inverted)
You now have the float height. I think its around 20mm
Do a search as this has been discussed before

And on the 7th day... Zeds were created!