Dual Diaphragm Power Brake Booster, 8 Inch, Chromate Finish

#91031435

Dual Diaphragm Power Brake Booster, 8 Inch, Chromate Finish

Name: Dual Diaphragm Power Brake Booster, 8 Inch, Chromate Finish
Brand: Speedway Motors
SKU: 91031435
Price: 160.99 USD
Availability: InStock
Rating: 4.8 (26 reviews)

26 Reviews

9 Questions

Compact for installation under floor or on firewall of almost any vehicle
NEW dual diaphragm booster measures 8" in diameter
Booster mounts with four bolts on 3-3/8" centers

Finish:

Zinc

Chrome Black

$160.99

/each

In Stock

Quantity

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Product Summary

Universal Fit, 5.25" Overall Thickness, 4" Rod Length

Compact for installation under floor or on firewall of almost any vehicle
NEW dual diaphragm booster measures 8" in diameter
Booster mounts with four bolts on 3-3/8" centers
Master cylinder studs measure 3-3/8" on center
Booster measures 5-1/4" thick from mount surface to mount surface

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Key Specs

MFG. Part #	91031435
Brand	Speedway Motors
Outside Diameter	8"
Material Type	Steel
Finish	Zinc

See more specs

Need To Know

Need help?

855.313.9176

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Speedway Motors 91031435 Details

Compact, 8" diameter for installation under floor or on firewall of almost any vehicle. Zinc chromate finish.

3-3/8" Bolt Pattern (Firewall Side)
3-3/8 Center to Center Bolt Hole (Master cylinder Side)
Uses adjustable pin
Great for installs on GM A, F, X, Body Cars with Big Blocks or Engines with tall headers

Learn more about the proper uses of residual valves by reading our tech article.Brake System Selection.

Charts

Booster Tech Tip (GIF)

Brake System Builder's Tip (JPG)

Specs

8" O.D.
5-1/8" main body length
10-1/2" overall length
Back of the booster to the end of the threaded plunger rod is 4-1/8"
Firewall mounting studs are ¾" long at 3-3/8" center-to-center
Front master cylinder studs are 1-1/8" long at 3-3/8" center to center

Guides & Documents

Brake Boosters Technical Information (91031435)

CA WARNING:

Can expose you to lead, a carcinogen and reproductive toxicant. See www.P65Warnings.ca.gov

Speedway Motors 91031435 Specifications

KEY SPECS
MFG. Part #	91031435
Brand	Speedway Motors
Outside Diameter	8"
Material Type	Steel
Finish	Zinc

GENERAL
Overall Thickness	5.25"
Bolt Hole Pattern	3.38" x 3.38"
Centerline of Holes	3.38"
Rod Length	4"
Brake Booster Type	Vacuum Diaphragm Dual
Sold in Quantity	Each
Notes	Dual diaphragm booster.

Ratings & Reviews

4.8

26 Reviews

Overall Assessment

Customers have consistently praised the product for its reliable performance and perfect fit. It's confirmed to improve braking power remarkably, proving superior to smaller, 7" models. Although a few customers had compatibility issues, the majority affirmed its ease of installation even on vintage cars, appreciating its quality and practicality. Its perceived value-for-money affirms it as a recommended purchase over competitive offerings.

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4.8

26 reviews

Most Liked Positive Review

5.0

I have brakes now.

I needed a small dia. booster to clear my tall valve covers. I bought a 7" at a car show and it didn't work. I'm not sure if it was bad or just too small. I ordered this 8" and my brakes work like new.

Most Liked Negative Review

1.0

Did not work for me

After numerous discussions with the tech. team, sent back my 7" single booster for this one. I was told the 7" booster was too small for my car(1962 Starfire). Installed this one and did not help at all. I had to buy another setup elsewhere as nobody could help me. Sent booster back, but had to keep the master cylinder as I listened to tech team. My advice is do your research well before buying anything.

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Sort Reviews

Direct replacement is nonexistent but this saved the day

5.0

a year ago

Mr.B

Mccook Ne

Verified

Universal part that fit perfect and works get. Great solution for older vehicles

Would Recommend

Brake booster worked great

5.0

a year ago

Jason

Forest Hill, Maryland

Verified

The product was easy to install and fit perfectly.

Would Recommend

Direct fit

5.0

2 years ago

Vintage racer 77

Pringle, sd

Verified

Made a big difference in braking power

Would Recommend

Yes

5.0

2 years ago

Joe

Lexington SC

It fit like it should, and works good.

Would Recommend

This product made me realize my old uniit never worked right

5.0

5 years ago

Steiny

York, Pa

Verified

This unit fit in my '55 Chevy perfectly. No issues.

Would Recommend

Did the job

5.0

5 years ago

Don

Verified

Did the job

Would Recommend

id buy this product over and over again,,,,

5.0

6 years ago

Tom

wisconsin

Verified

great place to do business,knowlegable staff,friendly,aim to please

Would Recommend

Yes fit great

5.0

6 years ago

Tweetie

Warwick ri

Verified

Perfect fit

Just as described

5.0

7 years ago

Mac

Fayetteville NC

Verified

I converted my std brakes to power brakes and this booster gave the perfect space around the tall valve covers. Also provides great stopping.

Would Recommend

Good product

5.0

7 years ago

Joe

Wisconsin

Verified

Good product, made a huge difference .

Would Recommend

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Showing 10 of 26 reviews

Questions & Answers

9 Questions • 9 Answers

Sort Questions

I have a 7 inch booster on my s10 and can't really stop my truck. I even adjusted the pushrod to the correct length and nothing. Will an 8" booster be any better?

by Nick

• 7 years ago

1 answer

View Answer

I need to replace the booster on my 1960 Olds Dynamic. 371 ps/pb car with drums all around. What modifications are required to use this unit in my application.

by LeadFreddie

• 10 years ago

1 answer

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I am replacing the booster and master cylinder on a 65 corvette and wanted to know if this booster would work

by gabriel

• 10 years ago

1 answer

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Does this brake booster have a vacuum check valve built in? I have installed this unit and Not getting good brakes on my car. Has mid size chevy disc brake in front and 10" ford in the rear. I get hint of good brakes once in a while but peddle seems to firm up as it would if you ran out of vacuum

by Mike1524

• 12 years ago

1 answer

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will the 8 inch booster directly mount to my 1968 camaro with wilwood master cylinder

by shamu

• 12 years ago

1 answer

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short or long pocket Brake Cylinder.? : Let me know if your booster works with both short and long pocket Brake Cylinder.?

by denoisy

• 12 years ago

1 answer

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Hi can I use this brake booster too my master cylinder/pedal assembly for model T,A 1932 part nr 91631926 Best regards

• 14 years ago

1 answer

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How long is it from the face where it bolts to the MC to the opposite face excluding the studs? I have your 7" booster now and need to know how much longer an 8" dual will be so I'll know what mods to make. thanks

by 41 chevy

• 15 years ago

1 answer

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I have 1964 F-100 with 223 six...need to know if this booster will directly bolt on to firewall or if it need an adapter ?

by slojet

• 15 years ago

1 answer

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9 of 9 questions shown