Enhanced Stopping Power: Experience a significant 20% increase in braking force with the 2-3/4\" piston, providing superior stopping power over standard stock calipers for 1978-88 GM vehicles., Amofferextrous Design: Equipped with 10mm-1.5 inlets for both the bleeder and inlet, these calipers can be universally mounted on either the left or right side, offering versatile application., Complete Kit Included: Each caliper comes with brake pads, slide pins, a banjo bolt, washers, and a bleeder screw, ensuring no additional parts are needed for installation., Optimized Construction: Featuring extra internal ribs for increased rigidity and reduced weight, these calipers offer a lightweight yet robust design, improving overall vehicle performance., Ready for Customization: The calipers are ground s 2-3/4 Inch Big Bore 1978-88 GM Metric Brake Caliper Sku # 91031040 Mfr. Part # 91031040 Condition New Brand Speedway Motors Sold Each Details
If you are using 1978-88 GM Metric style brake calipers your choices of piston sizes are pretty much limited to 2-1/2\". This isn\'t bad unless you want to \'tune\' your braking by using different size calipers front to rear. By using a larger 2-3/4\" piston you will increase the braking force at a wheel over a wheel using a smaller piston.
Bleeder and inlet are both 10mm-1.5 inlet allowing the caliper to be used on either side. Plus, these calipers have been ground smooth to make them easier to paint.
Includes pads and hardware. Sold as EACH.
- 20% increase in stopping power over stock calipers
- Can used on the left and right sides
- Extra ribs have been added internally while unnecessary weight was removed
- Lighter, stronger, has more stopping power than OEM calipers
- Utilizes
Specs Caliper Pistons One Piston Diameter 2.75" Sold in Quantity Each Bore Size 2.75" Centerline of Holes 5.50" Rotor Thickness 1.00" Finish Natural MFG. Part # 91031040 Material Type Steel Reviews Yes I would buy this product again. Rated by moneypit1961 on June 18, 2026
Summary: I replaced the original 2 3/8 calipers on my mustang 11 front suspension in my 33 Ford. Brakes were always just ok, could never lock up the wheels in a panic stop. I increased the master cylinder size from 7/8 to 1" and installed these 2 3/4" calipers. I now have a firmer, higher pedal and I can lock up the wheels. Not that I want to but I'm able to. And with a little grinding I was able to reinstall my 14" wheels. I am an NSRA safety team inspector so I was careful how much (little) I ground off the slide bolt ears. Very satisfied with the results.
Yes, I recommend this product.
Perfect OEM update. Rated by Richie on February 13, 2026
Summary: Swapped out both front calipers on my 02 2wd s10. Parts bolted right on and included brand new hardware to attach them AND PADS also. They are definitely bigger and better than the stock equipment.
Yes, I recommend this product.
I would buy again Rated by Colt on January 25, 2025
Summary: Quick to insult
Yes, I recommend this product.
Good for rear disc conversion squarebody Rated by Ew on January 14, 2025
Summary: Put these on the back of my 87 burb. Bigger piston than the standard Cadillac calipers, got my F/R ratio where I want it.
Yes, I recommend this product.
I will be purchasing this product again Rated by Nate on September 30, 2024
Summary: The build quality seems to be quite good and the part appears like they will be an upgraded part for my application.
Yes, I recommend this product.
Related Items / Suggested Parts DOT Braided Stainless Brake Hoses, 1978-88 GM, 10mm-1.5 Rubber Front Brake Lines & Fitting Kit, 10mm-1.5 Stainless Braided 19 Inch Front Brake Hoses, 10mm-1.5 1978-88 Replacement GM Midsize Metric Calipers 1978-88 GM Metric G-Body Brake Calipers, IMCA Approved, 7/16-20 Speedway 156 1978-Up D154 GM Metric Brake Pads Wilwood 130-12147 Caliper Slide Pin O-Ring Kit Speedway GM Brake Caliper Slider Slide Bolt AFCO 7241-9001 Oversized 2-3/4 Inch GM Metric Caliper, Right Hand Side AFCO 7241-9002 Oversized 2-3/4 Inch GM Metric Caliper, Left Hand Side Wilwood 120-8924 D154 GM Metric Iron Single Piston Floater Caliper Tech Support We\'re here to help before and after your purchase. If you have a question or need assistance with one of our products, please contact us through Messaging and a knowledgeable Speedway Motors team member will be happy to help. About Speedway Motors is America’s Oldest Speed Shop® and has been a trusted source for specialty rodding and racing products and friendly expert advice for more than 74 years. Founded in 1952 by “Speedy” Bill Smith – a racer and street rodder himself – Speedway has grown from a one-man operation to become the world’s largest manufacturer, distributor and retailer of street rod and racing products. Our industry-leading fast delivery is the result of same-day shipping from our state-of-the-art, centrally located 500,000 sq. ft. headquarters. Speedway’s size offers customers unmatched product selection and low pricing, while our excellent technical support and customer service have made us a recognized leader in the rodding and racing industries.
