02M box into 2011 Scirocco questions

[RJohnson]

I have got an LSD for a 02M 2wd, it came at a bargain price otherwise I would have just bought one to suit the 02Q. I want to fit it to my car, it appears it should fit my 02Q box, but one of the diff bearings will be 2mm too big on the inner diameter, I should be able to sort this with a suitable sleave, I have a lathe so stuff like that is all possible, that is plan A
For plan B  I have a 02M 4wd box from a 2002 Audi S3, I have removed the transfer box, plugged the transfer box oil supply and return, it also needs an oil seal for the offside driveshaft. The advantage of using this box is that I can build the LSD into that box and then "just" swap the boxes, I don't want the car off the road for long. I have a few questions for you knowledgeable people.
1.  I have seen some mention of the top gearbox mount being different on mk 4 chassis to mk 5/6 is this true, if so can it be sorted with a different mounting bracket ?
2. Tthe gear ratios in the 02M are from what I can find all a little shorter than the 02Q, I am fine with that, should help acceleration a bit, but will it cock up things like the cruise control and the gear indicator ?
3  Any other problems that are likely to crop up ?

[RJohnson]

well, I have an answer to the first question, gearbox mount is different, cant see any of the shelf bracket that will sort it so making a mounting to fit 02M box and Scirocco mount, a bit of 10mm plate and some spacers should solve the problem. It is a pig of a job to get the box out !

[xjay1337]

Mk4 gearbox in a Mk5 platform physically CAN fit (in some cases), but isn't designed to and ruins driveshafts.
Just buy the right parts for the car.... plan A perhaps would work, plan b is a no-no.

[RJohnson]

how will the older box ruin driveshafts ?  whilst there are detail differences between the 2 boxes they are basicily the same,
I ended up just refitting the 02Q box after 3 days of messing about trying to get the 02M to fit. I still intend to fit the LSD, and the job will be so much easier the next time !