450-520 is a pretty soft ride, i wouldnt expect that to perform very well. lower isnt always better. look into FORD springs. the C-springs have a good 650lb up front and 250 out back, its a good firm rate, and fairly cheap at 130 bucks
__________________ 1965 Mustang Coupe Project: 1965 Mustang Inline 6 (For Now) Coupe, New Floors, New Quarters | Ford 9 Inch Rear, 11" Rear Disc Brakes, 3.50:1 Gears | Control Freak Front U/L Control Arms, Global West Adj. Strut Rods | KYB Gas-A-Justs, Grab-A-Trak 620 Coils & Mid-Eye 5-Leafs | Global West Tubular Subframe Connectors | Addco 1-1/8 Front Swaybar Kit |