What does a BA Ghia V8 falcon have as a diff is it a m78 like the N/A 6 or is it a m86 like the turbos, and can you put a m78 centre into a m86 dif housing(probably not) but thought I would check as stranger things have happened

Pretty sure all V8's and turbos had the M86.

How do u tell?

Is it written on them?

Ta,

CrankR.

Ford diffs usually have a small metal tag on the bottom of the diff centre, apart from that I don't know how else you can tell bar the physical size of them. The 78 is 7.8 inches the 86 8.6 inches, with that being the size of the diff centre.

here is something that you might find useful

So if I get diff gears from a Borg warner M78 diff centre, like higher gears they would bolt to the centre OK or if I got a centre from something like a B/W that has the m78 model number it should bolt straight in.

so the m86's are LSD? how hard would it be for me get get a m86 on my n/a 6?

M86 into a m78 or n/a 6, you need whole diff centre housing driveshafts not sure on the brake backing plates, as the m86 is larger