400-500lbs lowering springs for a 1987 300zx
 

Looking for a set of 4 400-500lb lowering springs for a race only 1987 300zx. New or used. I can only locate the street car Eibachs or these:

http://www.ebay.com/itm/NISSAN-300ZX-300-ZX-inc-TURBO-Z31-84-89-1-25-1-25-LOWERING-SPRINGS-/171375604092?pt=Motors_Car_Truck_Parts_Accessories&fits=Year%3A1987%7CModel%3A300ZX&hash=item27e6c8317c&vxp=mtr
and neither are 400lbs+ which is what I am looking for. Will prob use the Bilstien shock/struts and avoid any coil over conversion like the ebay special Stance brand as I do not know the quality of that brand, and they may bump us into higher race class with the world racing league.

Also pm me your list of suspension mods you have done to your z31 that has resulted in a much firmer ride.

Thks, Todd