I had about 8 of these over a few years until about '92. From memory the following changes were made.
Early XF had the leaded motor in them , these went considerably better than the unleaded models.
I believe that about the time the EA was released there was a mechanical update done, with the following changes:
5 speed manual available as an option (Previously only 3 speed man or auto)
All vans fitted with windows, blank side panels no longer available. ( I dont know why they did this, It caused us some problems and we ended up getting the windows tinted as dark as possible)
Tailgate style rear doors dropped and only barn doors available.
LSD was always an option and all my vans were so equipped
TYHere were several changes to the front bumper assembly, chronologically listed:
Grey Bumper, no blinker repeaters in sides. (leaded model only IIRC)
Grey bumper, blinker repeaters fitted
Grey bumper, Colour coded below actual bumper,blinker repeaters fitted
Complete colour coded bumper with grey grille, blinker repeaters fitted
Grey bumper, Colour coded below actual bumper, colour coded grille,blinker repeaters fitted
Hope this is of some use. I dont believe that XF vans were ever fitted with 4 speeds as they were dropped from the XE range with the S pack and the five speed was introduced when they finally ran out of 3 speed manuals.
I got a four wheel drive after they had to spend $2000 rebuilding the front end of my last van so I never got an XG or an XH.