how much sag should there be in a 04 vertical edge ? we put new torsion springs in (the heavier set) and it still sags really easy for about 6 inches then gets stiff or normal compared to other sleds i ve had? is this normal for this machine? the torsion blocks are cranked to the max as well. the skid is in the furthest back hole in the front of the tunnel and the secound back in the back or the tunnel. Any help would be great