Cylinder Map 400CDI V8

I’m replacing the no 5 and no 8 injectors of my MB400CDI V8 diesel.
Can someone please help me with a map over the cylinders and how they are numbered?
I asked my mechanic and he says it’s different from petrol to diesel and from brand to brand how they number the cylinders. I’m not sure which cylinders are no 5 and no 8.
Thanks


