why does the over center spring have to be removed

just had a McLeod diaphragm clutch installed in my 73 340 duster. I noticed that they never took out the over center spring. I had a 3 finger borg and beck in there before that was super stiff pedal, any how I noticed the pedal only has to go a bit over half way down to the floor to shift it. also the pedal comes back up real fast when you are leaving from a dead stop, is this because I am not use to it or is it from the guys not taking that over center spring out?? from what I have read here, when you put a diaphragm set up in the spring should be removed. need some help here thanks much