Unimog Club UK

the figures depend very much on what eara of B series 411 they are quoting from, i believe the early 411 B's (32 HP) were fitted with pressed axles, pressed axles are much lighter than 3 piece axles, hence the weight difference between the b and c.
This will also explain the weight similarities with the 404 and 411 C, the 404 has pressed axles, lighter than the 411 C's three piece axles, but the weight gained in the chassis length on the 404 balance's it out

and dad says the 6 cylinder M180 lump is heavier