Ok guys here's the go

The stud pattern is 5/114.3 5 is the number of studs and 114.3 is the
mesurement in mm from one stud diagionally across to the opposite side.
So all falcons from the earl XY to current BA have the same stud pattern
so do other manufactures like hilux (2wd), magna, camry, honda crv even the old vals (go the chargers!!) (but the vals have a larger bore size to fit over the hub).

Offset is the measurement that determines where the wheel sits in relation from the hub. Pre AU cars like XD/XE/XF have a large boss on the back of the mag which is part of the mag (ie in the mould).

If you need spacers, THIS IS ILLEGAL, for street use, no matter what the
wallies at bob jane or quickfit say, its in the transport legistation and your
insurance company won't pay up if they find out and you need to claim.

AU and onwards have a much small boss on the back of the mag and hence sit alot flusher with the guard. AU offset is +35. Also if your tyres exceeds the guards by more than an inch in qld its illegal too.

other stud patterns include
5/120 commodore from VH to VT including munaro (but its offest is different) VX I'm not sure on (but who cares anyway) some BMW but the boss size is different c/dore won't go on a bmw but bmw fits c/dore.

6/139.7 Hilux 4wd, landcruiser with 6 stud, pajeo(spanish for wanker, pronounced "pe care o") patrol

5/100 new landcriser 4/114.3 hy excel/elantra/accent 4/100 corolla, lancer bla bla bla.

Just to finish of locating rings are important (little bits of plastic rings that sit inside the inner boss of the mag), these are supplied by mag wheel manufactors to help centralise the mag on the hub, because, they make mags with one bore size that fits many different vehicles. Without these rings chances of vibratation problems are increaced and extra stain on the studs may occur if the wheel is not tightened on straight.
These are found more on small four cyclinder cars but some 10 hole multi fit (c/dore and ford stud pattern) mags may have them also.

Hope that clears up some things for you

i had TS50 wheels on my XH. the fronts off the TS went on the back with no problems except they sat way in to what i've got now. and the rears off the TS went on the front with big problems. i had to use an 8mm spacer for the TS50 rears to fit the front of my XH. even so in doing that, i still had to put the next size tyre down in width on so it cleared. but otherwise they wont be going on. end of story

i pretty sure u will also find that pre xd also has a slightly different offset to the xd models