Ok so I'm new here and have had a bit of a read of the post's on the KE20's and the diffs. Well the time has come to replace my stock 20 diff. The car is running a Blue Top 4AGE with no modifications. I have been reading that the T series would be ideal only problem is trying to find one. So brings me to the question How good are the S Series diff's and the E series? Also considered putting a 105 series Alfa diff in which would only require the shorting of one side has anyone done this before? Also i assume that it is not possible to put a T series head in a S series housing? Any opinions would be appreciated.