Here is the ratios comparison, in case anyone is interested:
US 5-speed European 6-speed
---------- ----------------
3rd 1.231 1.320
4th 0.993 1.034
5th 0.730 0.857
6th 0.730
Final drive is 4.11 for both.
Hoppen sells a conversion kit for $3990.00.
Dave
'92 S4