Quick answer: if you’re upgrading a GM 10 or 12 bolt rear end, a bolt-on rear disc kit is usually the most straightforward path to improved stopping power and modern handling. The top options below are suited for mid-size cars, GM A- body platforms, and select classic trucks. Each kit includes hardware and rotors, with varying compatibility and installation requirements. This guide highlights who each kit is best for and why it was selected, plus practical cautions to consider before buying.
| Product | Best For | Key Benefit |
|---|---|---|
| Speedway Motors Bolt-On Rear Disc Brake Conversion Kit | GM 10/12 bolt mid-size cars | Cost-effective, complete bolt-on kit with caliper brackets, vented rotors, and hardware |
| JEGS GM 10 & 12 Bolt Rear Disc Brake Conversion Kit | Standard shock configurations on GM 10/12 bolt axles | Simple bolt-on upgrade with parking brake option |
| BST BSSP GM 10 & 12 Bolt Rear Disc Brake Conversion Kit | Classic GM axles in mid-size cars | Detailed fitment and comprehensive mounting measurements |
| Inline Tube 1978-87 GM G-Body Rear Disc Conversion | G-Body platforms needing cross drilled/ slotted rotors | Includes calipers, lines, hoses, and hardware for a coordinated upgrade |
| Auto City Classic Rear Disc Brake Conversion Compatible with 1967-1986 C10 | Classic GM C10 pickups | Thorough compatibility with late-’60s to mid-80s trucks |
Speedway Motors Bolt-On Rear Disc Brake Conversion Kit
The Speedway Motors kit is an affordable bolt-on option designed to upgrade GM 10 and 12 bolt rear ends in mid-size cars. It includes two bolt-on caliper brackets, two vented rotors, two GM metric calipers, and all necessary hardware. Best for buyers seeking a cost-conscious, complete upgrade that minimizes fabrication.
Who it’s best for: DIY enthusiasts who want a straightforward install on mid-size GM 10/12 rear axles. Why selected: it provides a ready-to-install package with essential components, reducing sourcing time. Caution: not suitable for full-size cars, pickups, or 7.5″ 10 bolt axles.
Auto City Classic Rear Disc Brake Conversion for 1967-1986 C10
This kit targets classic GM C10 pickups from 1967 to 1986. It’s a comprehensive conversion with parts designed to fit a traditional truck rear end. Best for classic truck restorations or upgrades where authenticity and compatibility with older C10 components matter.
Who it’s best for: owners restoring or maintaining classic C10s. Why selected: focuses on a traditional pickup platform with relevant fitment. Caution: verify rotor and caliper compatibility with your exact axle configuration before purchasing.
JEGS GM 10 & 12 Bolt Rear Disc Brake Conversion Kit
The JEGS kit offers an easy bolt-on solution for upgrading from drum to disc brakes. It fits most 10 & 12 bolt rear axles and includes plain rotors and loaded calipers. Best for buyers seeking a straightforward conversion with a simple, broadly compatible setup.
Who it’s best for: enthusiasts upgrading older GM Axle configurations with a focus on simplicity. Why selected: emphasizes ease of installation and broad compatibility. Caution: ensure the provided parking brake configuration aligns with your vehicle’s system if needed.
BST BSSP GM 10 & 12 Bolt Rear Disc Brake Conversion Kit
This BST BSSP kit is tailored for GM 10 and 12 bolt rear ends in mid-size cars. It includes precise mounting fitment details, addressing both top and bottom bolt hole centers. Best for buyers who want explicit, documented fitment data to minimize installation ambiguity.
Who it’s best for: owners needing clear mounting specifications and reliable alignment. Why selected: emphasizes accurate fitment guidance. Caution: not intended for full-size cars, pickups, or 7.5″ 10 bolt axles; verify your axle specs first.
Inline Tube Compatible GM G-Body Rear Disc Conversion
The Inline Tube kit is designed for 1978-87 GM G-Body platforms. It features cross-drilled and slotted rotors, included calipers, cables, lines, hoses, and hardware. Best for buyers seeking a complete, integrated upgrade with premium rotor design for improved cooling and braking performance.
Who it’s best for: G-Body owners aiming for a comprehensive, technically coherent package. Why selected: combines rotors, calipers, lines, and hardware in one kit. Caution: verify compatibility with your specific G-Body model and parking brake setup.
Buying Guide: Key Considerations For Rear Disc Conversion Kits
Evaluate axle compatibility first. Most kits target GM 10/12 bolt rear ends or specific platforms like G-Body or C10 trucks. Confirm your axle diameter, bolt pattern, and spacer needs before purchasing.
Kit completeness matters. Look for a package that includes calipers, rotors, brackets, lines, hoses, and hardware. A complete kit reduces the need for sourcing separate parts and speeds up installation.
- Why bolt-on matters: Bolt-on designs minimize fabrication, making the upgrade accessible to DIY buyers.
- Rotor design: Cross-drilled or slotted rotors can improve cooling and pad bite, but ensure you’re using compatible pad compounds for best results.
- Parking brake compatibility: Some kits include a parking brake mechanism, while others assume a separate system. Verify this if you rely on a parking brake for safety.
Budget vs. performance: more affordable kits offer value and speed-to-setup, while premium kits emphasize precise fitment and enhanced rotor design. Choose based on driving style and intended usage—daily driving versus weekend projects.
Installation considerations: check whether your rear end housing and shocks require adjustments or if the kit provides mounting brackets that fit your shocks’ configuration. Consider whether you need a “loaded” caliper with pads and hardware versus a bare caliper.
Frequently Asked Questions
- What is a rear disc conversion kit?
It replaces drum brakes with disc brakes on the rear axle, typically including rotors, calipers, brackets, and hardware. - Will a rear disc kit fit my GM 10/12 bolt?
Many kits are designed for 10/12 bolt rear ends, but verify the exact bolt pattern and axle size for your model. - Do these kits require professional installation?
Some installations are suitable for confident DIYers; others may need professional alignment or brake bleeding for safety. - Is parking brake included in all kits?
No. Some kits include a parking brake assembly, others require a separate solution. - What maintenance is required after upgrading to discs?
Regular rotor and pad inspection, fluid checks, and brake system bleed as needed to maintain performance. - Can I reuse original brake lines?
Most kits provide new hoses; reuse should be avoided to ensure reliable seals and performance.