Wilwood Disc Brakes has added XRS4R rear big brake kits for the Big Ford New Style 2.50-inch offset axle flange, with MSRP starting at $2,714.00 for the mechanical parking brake version and $4,135.29 with an electric parking brake. The kits are part of the first application round for the company’s new XRS X-Bridge caliper, which Wilwood says is stronger and lighter than the Forged Narrow Superlite (FNSL) radial-mount caliper it succeeds. Buyers choose between 12.88- and 14.00-inch rotors in either parking brake configuration.
Highlights
- Two rotor sizes: 12.88-inch rotors with 48 curved internal vanes or 14.00-inch rotors with 72
- Two parking brake options: Internal drum parking brake in the hat, or EPB with wiring harness, control unit and remote switch
- Pricing: From $2,714.00 (internal parking brake) and $4,135.29 (EPB)
- Fitment: Bolts directly to the Big Ford New Style 2.50-inch offset rear axle flange
Kit Configurations
| Rotor | Parking brake | Base part number | Starting MSRP |
|---|---|---|---|
| 12.88 in | Internal drum | 140-18293 | $2,714.00 |
| 14.00 in | Internal drum | 140-18294 | $2,714.00 (group starting price) |
| 12.88 in | EPB | 140-18295 | $4,135.29 |
| 14.00 in | EPB | 140-18296 | $4,135.29 (group starting price) |
What Does the EPB Option Include?
The electric parking brake version replaces the internal drum assembly with Wilwood’s EPB caliper and ships with the wiring harness, control unit and remote switch. Wilwood introduced expanded EPB caliper sizes as stand-alone units in 2023, and the company has since offered the system as an option on rear kits including its recent K5 Blazer packages.
In the standard version, separate lightweight aluminum hat assemblies house the internal parking brake assembly.
Caliper, Rotor and Pad Specifications
The XRS4R is the four-piston version of Wilwood’s Next Evolution X-bridge street caliper. According to the company, stainless steel pistons and a square O-ring design provide better heat barriers and longer component life, with improved performance and pedal feel. Calipers come in gloss red or gloss black powder coat, with other colors available at additional cost.
Rotors are Wilwood’s black E-coated Spec37 iron alloy in GTB slotted or SRP drilled-and-slotted designs. The 12.88-inch rotor uses 48 curved internal vanes and the 14.00-inch rotor uses 72, according to the release. Kits include BP-10 street-performance brake pads; other compounds are available for most applications.
The Big Ford New Style kits join three XRS kit groups for 1963–1987 Chevy C10 trucks released the same day.
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