Firstly this is a how to dealing with welding a centre diff BUT allowing the retaining of the front axles so to make it easier to pass a WOF without to many questions.
Now for the warnings I take no responsibility about any damage done to the vehicle or person whom under takes this mod .
You will need to take the centre diff out of the gearbox, this can be done with gearbox in car
This is the centre diff as it should look (this one is from a 93ish GT so yours may look different)
Dismantle the centre diff by removing the circlip I would also remove all bearings if u wish to reuse them,
You should now have 3 bits the carrier, the drive flange and the viscous coupling, u will need to cut part of the viscous coupling of to negate the front drive
After some measurements I figured out that a length of 20mm would work best
Marked
Cut
The 2 parts now, a wee clean up and looks good I used a 4" grinder with a 1mm cutting disk on it,I would suggest having it parted of in a lathe but mine is only a wee hobby lathe
All back together and welded at the spider gears
Put back in and go do a some skids