Le Mans 1000 float height

Anyone know the float height for Le Mans 1000 40mms?
Have a Haynes manual that says 23.5 for Le Mans 1 36mms. This old tractor says 18,5+17,5 (what does it mean? 36??)

The Haynes manual gives the wrong float setting for 36mm phf carbs as fitted to the le mans
this old tractor has the correct setting for 36mm carbs.
I dont know about 40mm carbs but my dellorto manual only lists a float height of between 18.5 to 17.5
for phf carbs.
The float height in the Haynes manual is for the vhb carbs.