A 2' bar welded onto the MMC supplied socket delivers the right torque for tightening up, I have a 6' sleeve to fit over the bar for un tightening them and this has worked for the 5 years ownership.
When I did know the correct torque I worked out it required a 2' bar but I can't remember the figure now.

This is my ex 4/4 Sport bar and socket from Millers, which is spot on for loosening the nut when slid over the 2' bar.

Regards Richard

1999 Indigo Blue +8
2009 4/4 Sport Green prev
1994 Connaught Green +8 prev