Originally Posted by
dabow
just a quick one api, you put uk diffs are 3,545. but before i changed my uk95 early classic to a ty754. most if not all the rear diffs came up as 4.11 & the australian ones were the 3,545
i dug up what i throught was every thing to find out any issues refgards changing things over.
the only differnce to changing from a ty752 & the 54 is you need to thread the casing on the lower bolt to fit the starter on.
and the casing is a little tight when fitting if you have a td05
apart from that. is there anything else needed?
this link is some thing very simmerler to what i looked at.
but very helpful:
The SPDA - Transmission Chart
RIGHT: Once again; 
ALL UK 5 speed transmissions have 3.9 front ratio and 3.545 rear ratio with a 1.1:1 step off. No other 5 speed transmission final drive has ever been offered on a UK car [ P1 aside, as that is an STi 5 in disguise ]
Anyone / any website that tells you otherwise is wrong.
4.111 is a JDM ratio WRX any year from 1993 to 1999.
No point in getting into Aussie stuff, it is not relevant here
David APi