PB8531C | Universal 8" Dual Diaphragm Chrome Booster

PB8531C Universal 8" Dual Diaphragm Power Brake Booster: Chrome

Get strong stopping power and show-quality looks in one compact booster. The PB8531C packs two diaphragms into an 8" booster, so it delivers the firm, confident pedal of a much larger unit in a smaller package. Its bright chrome finish dresses up any engine bay, making it a natural fit for street rods, muscle cars, and show cars where every part under the hood is on display.

The compact 8" size clears tall valve covers, big-block engines, and aftermarket heads that often get in the way of a full-size booster. It uses standard GM bolt patterns, including the 3-3/8" square firewall pattern, so it works with common GM master cylinders and mounting brackets. Paired with the right brackets, it fits a wide range of classic GM cars.

Booster only. Mounting brackets, pedal rod extension, clevis, and master cylinder are not included. Choose the brackets that fit your vehicle, or reuse your existing brackets if they match the 3-3/8" square pattern.

Features

• 8" dual diaphragm design for strong braking assist
• Show-quality chrome finish
• Compact size clears tall valve covers and big-block engines
• Standard GM bolt patterns, including the 3-3/8" square firewall pattern
• Universal fit with the correct mounting brackets
• Vacuum tested and quality inspected before shipping

Popular GM Applications (with the correct brackets)

• 1955–1957 Chevy Tri-Five: Bel Air, 210, 150, Nomad, and Sedan Delivery
• 1958–1970 full-size Chevy: Impala, Bel Air, Biscayne, and Caprice
• 1964–1972 GM A body: Chevelle, Malibu, El Camino, GTO, LeMans, Cutlass, 442, Skylark, and GS
• 1967–1972 GM F body: Camaro and Firebird
• 1968–1972 GM X body: Nova and Ventura II
• Street rods and custom builds that use GM-pattern brackets

Fitment depends on your brackets, pedal assembly, and master cylinder. Always confirm your setup before ordering. Prefer black? See the PB8531PC in black powder coat.