Have you read my ad and the web information at Maxford USA, They are both 38 inches-tip to stern
If you REALLY need 40" then buy them from Maxford but get it in writing that they are 40 in--tip to stern.
From my investigation they have no 40" floats on their website.
they maybe including the added length of the rudder. This does not make them 40" floats.
Good luck