Mk7 Jumbo dual rears Ford specifications

[rossco_pb]

My van has the GVM of 4490kg (motorhome on chassis) and am interested if possible to increase it. The people who do that type of work here in NZ said they would need the Ford specifications on basically how the van has been built, tolerances etc so see if anything can be tweaked. They have the info for 2014 onwards but nothing for the MK7. Anyone know of any such documents and/or how to obtain them?

Cheers