Z33 G35 Z34 G37 Subframe Solid Bushing Riser ~ Now sold in Gold anodized aliminum (formerly black delrin) ~ Slide in from the bottom to raise the subframe up against the chassis. This will help flatten your control arms and axles on lowered cars. ~ Formula D Rulebook legal if you use the included OEM height top spacers, slotted for easy install ~ The front top spacers are 0.6" thick and the rear top spacers are 0.3" thick as per FD rulebook requirements. * use washers on the OEM nut to make sure it does not bottom out when using these in the raised subframe configuration