Wilwood Street Performance FNSL6R BB Front Brake Kits (Hub), Drilled for a 58-70 GM, 14" Rotor

Wilwood’s FNSL6R Front Brake Kit (Part #140-10238-D) is designed for 1958–1970 GM muscle cars running 17-inch or larger wheels and Classic Performance Products drop spindles (P/N 30101). The kit uses billet-forged Superlite 6R six-piston callipers and large 14-inch vented rotors for improved brake torque, heat dissipation, and durability. Made specifically for non-ABS applications, this system helps manage higher brake temperatures and offers consistent stopping power for street and dual-use vehicles. The forged construction provides strength while keeping weight reasonable. The kit’s bolt patterns (5x4.50, 5x4.75) and radial calliper mounting allow for a secure factory-like fit and easy installation.

KEY SPECS

- Fits: 1958–1970 GM cars with CPP Drop Spindle (P/N 30101)
- Calipers: Wilwood Superlite 6R, six-piston, radial-mount
- Rotors: 14” diameter, 1.10” thick, vented, slotted/drilled (with -D suffix)
- Bolt Patterns: 5x4.50”, 5x4.75”
- Wheels Needed: 17” diameter or larger
- Caliper Inlet: 1/8-27 NPT

INSTALLATION DETAILS

This kit should be installed by someone with disc brake experience. Start by removing the stock brakes and cleaning the spindle. Mount brackets and hubs, torque all hardware with threadlocker as described in the instructions, and install callipers using supplied shims for correct rotor spacing. Wheel studs, bearings, and grease seals are pressed and packed according to the included guide. The system does not include brake hoses—OEM lines are incompatible, so braided steel brake lines with the proper adapters are required. Once assembled, bleed the brakes carefully and follow detailed bedding instructions to ensure proper function and pad seating.

FACTORY FIT NOTES

- Designed for 1958–1970 GM models with non-ABS and CPP Drop Spindle (P/N 30101)
- Requires 17” or larger wheels due to calliper and rotor size
- Supports both 5x4.50 and 5x4.75 bolt patterns
- OEM brake hoses will not fit—use steel adapter fittings and braided steel lines
- Compatible with factory disc brake master cylinders, though front/rear bias may require tuning
- Not compatible with silicone DOT 5 brake fluid; use DOT 3 or higher