Wilwood Left Black 15.50-inch GTB Rotor, 1.38-inch Width and 60 Curved Vanes

The left GTB version has a 15.50-inch outside diameter with a 1.38-inch friction width. A large 9.64-inch center register and twelve-on-10.25-inch mounting pattern define its separate-hat interface. This component comes from Wilwood Engineering, founded by Bill Wood in 1977 and based in Camarillo, California. Wilwood designs and manufactures disc brake systems, including calipers, brake rotors, master cylinders, valves, fittings and brake lines for motorsport, street-performance and specialized applications, with compatibility determined by the complete brake assembly.

Technical Details

• Manufacturer part number: 160-13790-GTB
• Diameter and thickness: 15.50 inches diameter x 1.38 inches wide
• Ring material: Spec-37 Iron
• Face pattern and coating: GT Slotted; Black electrocoat
• Internal layout: 60 CV; curved
• Mounting direction: Left-hand
• Balancing and burnishing: Factory burnished no; balanced yes
• Opposite-side component, ordered separately: 160-13789-GTB
• Rotor-to-hat/hub attachment circle: 12 x 10.25 inches
• Attachment hole size or thread: 0.326 inches
• Center / lug registration: 9.64 inches
• Far-side inside diameter: 11.05 inches
• Approximate component weight: 24.80 lb
• Quantity: one rotor ring; hat, hub, mounting hardware, calipers and pads are separate

Fitment & Compatibility

The large 10.25-inch twelve-bolt circle and 9.64-inch register require the appropriate separate hat. Check the complete 15.50-inch assembly for wheel clearance and the 1.38-inch section for caliper alignment. This is the left-hand 60-vane ring; its black finish does not change the underlying Spec-37 material.

Manufacturer reference: Wilwood rotor specifications

PMB Performance has over 20 years of experience helping customers select brake components. Supplying the kit number, mounting dimensions and intended use makes that fitment check more useful.