I also did not change the transmission or the rear axle. I believe that if you change the transmission you also have to change the transmission control unit. If you do this you most likelly will have to change the rear axle to 3.07.
May be I'm getting something wrong here, but wasn't that what Max (evil_deeds) had done to his car?
Changing engine and transmission to the V8 version, but keeping the original rear axle with the 3.27 gearing.
Humphrey Bogart: The trouble with the world is that it's always one drink behind.