I managed to get a bit of time at the weekend to have a look at levelling the QL system, its really easy job and after doing mine it took ten minutes to do my Bro's.
At first I tried 1/2" cut out the connecting rod as recommended, but this dropped the rear way lower than the front, so we had another go with only 1/4" cut out and it brings it almost level (in park mode there's 2" arch gap and 2.5" at the rear) which is about right.
How to - - Get yourself some 8mm I.D steel tube.
Locate the QL servo (Pic Below), pop the ball joints off, these are only plastic so just pull off, cut 1/4" out the tube, cut from the middle as the ball ends go about 1/2" up the pipe. Now measure the length between the ball joints of the two bits of pipe and cut the steel tube to this length, slide the ball joints into the pipe and crimp the ends in vice.
Hope this helps, if you more information let me know.