hi, i've put an ed engine into a cortina so putting an i6 into an xc wouldnt be that difficult. you should be able to use xg/h engine mounts. i'd probably use an xg/h loom as well as it would be close to the right length etc. if u wire everything up as per original then the only problem that i can think of that u'll come up against is the smartlock but there are plenty of ways to overcome that.
the mounts and loom will get u 80% there and yeah u'll have hassles. if it were that easy more ppl would have done it. the wiring will be the biggest bitch. i did it and the only electrical qualifications i have are that i can read a wiring diagram and use a slodering iron. i'd advise to get the diagrams for both the engine u use and an xc. to get around the smartlock, use an ea ecu and if u'r using an ef engine u'll need to use an earlier model distributor. that should get u around most of it. there was so much to the conversion i cant remember every little hassle i had. u will have to wire in an electric fuel pump. i modified my fuel sender and used a vn commodore in-tank fuel pump. another hassle u need to check is radiator clearance. the i6 is longer than the ole crossflows, i'm not familiar with the xc's but i had to convert to electric water pump to overcome the clearance issue. u need to have two fuel lines(inlet and return), i made an air induction setup, i was able to use my old cortina tailshaft with the T5(had to have one made for the 9inch). use a cleveland radiator and i reckon u'll be home and hosed.
Smartlock = EB serII and onwards, very simplistically, the ignition barrel sends an enable signal to the computer when the correct key is inserted.
EA you won't have an issue with this.
Fuel pumps - The EA uses a submerged electric pump, so you would either have to adapt your tank to suit, or use an aftermarket one with the correct pressure and flow rates.
Radiator should run it cool enough, where are the inlet/outlets though? EA, the inlet (bottom) hose is on the driver's side and the outlet is on the passenger side.
Umm, as far as the tranny cooler goes, do you already have one? If not, you might be better making the EA radiator fit as it has an inbuilt tranny cooler.
Exhaust probably wouldn't fit.
Your intake snorkel will require some ingenuity.....
What about gearbox length, will the shifter match up with the hole in the floor?
Does the old tailshaft yoke fit the new box?
Where are the heater hoses on the XC, passenger side yes? That should work.
Wiring the EA computer loom up will, of course, be tricky. But possible.
Will the bonnet be high enough?
OK that's all I can think of right now
bonnet will easily be high enough. the majority of cleveland radiators had inbuilt trans coolers, but theres a shitload of room in front to fit a good cooler. if you use thermo fans you should be right. xd or xe onwards had an electronic (not digital, electronic) speedo, xc's have a cable drive speedo. the exhaust should fit. especially if you use xg/h. i think you can use a vn commodore wagon pump. they're different to the sedan ones, and are mounted outside of the tank. as for the shifter, it isn't too hard to modify the linkage for length. especially if you have a welder.....
good luck with it, i think its a damn good idea.
hmmmm...... theres a tidy xc fairmont sittin in my back yard not being used at the moment....lol