Ordering Information, Dynamic Mount Drilled Steel Rotors:
Diameter	Width	Bolt Circle	Hole Type	Lug I.D.	Bolt Kit	Weight LBS	Rotor Type	Part Number
12.90" (327,7)	.38" (9,7)	12 x 8.75" (222,3)	SLOT	8.25" (209,6)	230-4900	5.7	SSP	160-4766

Dynamic Mount Drilled Steel Rotors:
Dynamic mounting is the most effective method of eliminating all types of thermal stress and distortion in steel rotor applications. These rotors are machined with mounting slots that are used with special t-nuts and bolt kits. This mounting system allows the rotor to expand and contract independently of the mounting hat or hub as the rotor goes through temperature changes. This eliminates all strain or bind at the mounting points. The rotors run truer, last longer, and all undue stress on the hats or hubs is eliminated. Dynamic mounting is preferred in all applications where temporary, but extreme temperature spikes may cause high expansion rates in the steel. Wilwood also offers slotted dynamic mount hats and plates that are used to provide the "float" with a standard hole mount rotor, but the rotors in this category are machined for use on " fixed" mounts that require the "float" to be placed within the rotor itself.