So how could it carry three SC 1000 or two SC 1800, as e.g. the He 111 H-11 Flugzeug Handbuch shows?
Ummhhh... I do not have a specific book on He111. My sources are "Bombers of World War II" edited by David Donald of 1998
In this book is mentioned a bombs load of 2500Kg for H-5 and 3000Kg for H-21 with Jumo 213 engines.