Where did you get that rack from?....Looks shorter than a normal mustang II rack.I don't think anyone else makes a lightweight one for our cars. The others all seem to be more street/road race oriented. You can get alot of weight out of the stock one if you have the fabrication ability.
I got about 55lbs out of just the subframe on mine. Then add the tubular a-arms, rack, brakes, radiator support, etc.