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Flowtech 11546FLT SBC Upright Derby Headers, 1-3/4 Inch

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#42511546FLT

Flowtech 11546FLT SBC Upright Derby Headers, 1-3/4 Inch

Name: Flowtech 11546FLT SBC Upright Derby Headers, 1-3/4 Inch
Brand: Flowtech Exhaust
SKU: 42511546FLT
Price: 373.95 USD
Availability: InStock
Rating: 5 (3 reviews)

3 Reviews

1 Question

Has a 3” collector for maximum strength and exhaust flow
The CNC Mandrel-bent tubes provide consistent tubing diameters for smooth flow
Features heavy duty 16-gauge 409SS tubing for increased strength and durability

$373.95

/set

In Stock

$415.95

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Product Summary

Upswept Header Tube Type, Square Exhaust Port Shape

Has a 3” collector for maximum strength and exhaust flow
The CNC Mandrel-bent tubes provide consistent tubing diameters for smooth flow
Features heavy duty 16-gauge 409SS tubing for increased strength and durability
Includes an extra thick header flange for a leak-free seal and maximum strength
1-3/4” tubing diameter increases exhaust flow performance and improves throttle response

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Key Specs

MFG. Part #	11546FLT
Header Tube Type	Upswept
Exhaust Port Shape	Square
Flange Style	Standard
Primary Tube Diameter	1-3/4"

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Need To Know

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855.313.9176

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Return Policy

Flowtech Exhaust 11546FLT Details

Get the perfect combination of quality and value with FlowTech Upright Derby or Truck Pull Style Headers. Features a 1-3/4” tubing diameters and are ideal for even big cubic inch Small Block Chevy engines.
Also features a merged collector coupled with a collector spear that is welded inside the collector. These components help to improve the flow and performance of the header.

Features:

CNC Mandrel-bent tubes provide consistent tubing diameters for smooth flow and increases the cylinder scavenging effect and improves engine breathing
Heavy duty 16-gauge 409SS tubing for increased strength and durability
1-3/4” tubing diameters available for increased exhaust flow increasing performance and improved throttle response
3” collector for maximum strength and exhaust flow
Extra thick header flange for a leak-free seal and maximum strength
Welded-in collector merge spears to control exhaust gas re-entry into primary tubes
Gaskets and hardware sold separately.

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Holley October Promo 10% Off Select Parts Sale

Holley's October Promo 10% Off Select Parts Sale, running from September 28, 2026, through November 1, 2026. For a limited time, customers can save up to 10% off on select Holley parts, making it the perfect opportunity to upgrade your ride with premium Holley branded parts including Holley, Brawler, Quick Fuel, Leg Wheels, Rev Wheels, Rocket Racing, Flowtech, Edge, Racequip, Apr and Dinan. Purchases must be made between September 28, 2026, through November 1, 2026. This limited-time offer applies to qualifying Holley branded parts purchased during the promotional period. Following the promotion, these parts will revert back to standard pricing.

Guides & Documents

Choosing the Right Headers

CARB Warning

For race/ off road use only

Emissions warning: this part only legal for sale or use in California for racing (competition) vehicles which may never be used, registered, or licensed for use upon a public highway. Any other use renders the vehicle tampered and not legal for use on California public highways (any public street or roadway, public dirt road, public park, or publicly maintained right of way open to the use of the public for vehicular travel). Violations subject to $37,500 penalty per violation per vehicle, revocation of registration, loss of use on California public right of ways, and proof of correction for tampering. There are similar restrictions and penalties under federal law and the laws of all other states with penalties under federal law of up to approximately $45,268 per tampered vehicle and/or engine.

CARB warning

Flowtech Exhaust 11546FLT Specifications

KEY SPECS
MFG. Part #	11546FLT
Brand	Flowtech Exhaust
Header Tube Type	Upswept
Exhaust Port Shape	Square
Flange Style	Standard
Primary Tube Diameter	1-3/4"
Material Type	Stainless Steel
Color	Natural
Weld-Up	No
Collector Diameter	3 Inch
Finish	Raw
Hardware Included	No
Gasket(s) Included	No
Collector Reducers Included	No
Collector Attachment Type	Slip fit

GENERAL
Sold in Quantity	Set
GTIN Code	090127734964
Collector Length	12"
Emission Code	3

Ratings & Reviews

3 Reviews

Overall Assessment

Customers highlight the exceptional quality and construction of our product, particularly noting the heavy flange's effectiveness in preventing warping. The stainless headers are praised for their unbeatable value for money. Many confirm they will repeat purchase, proof of their high confidence in our product versus competitors.

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3 reviews

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I will buy this set again

5.0

a year ago

Iowa

Verified

Great Product

Would Recommend

heave flange

5.0

6 years ago

derby driver

new york

Verified

they look awesome the flange is heavy should help from warping they are very well put together

Awesome

5.0

8 years ago

Joe w

Tuckerton nj

Verified

I'm buying another set great product and you can't beat the price for stainless headers

Would Recommend

Showing 3 of 3 reviews

Questions & Answers

1 Question • 1 Answer

Sort Questions

Will these clear the factory brake booster on an 80's chevy 4x4

by Gearhead204

• 8 years ago

1 answer

View Answer

1 of 1 questions shown

Fitment

1959 Chevy 3A

2-Piece Rear Main Chevy 283

1959 Chevy 3B

2-Piece Rear Main Chevy 283

1959 Chevy 3C

2-Piece Rear Main Chevy 283

1959 Chevy 3D

2-Piece Rear Main Chevy 283

1959 Chevy 3E

2-Piece Rear Main Chevy 283

1959 Chevy 3F

2-Piece Rear Main Chevy 283

1959 Chevy 3G

2-Piece Rear Main Chevy 283

1957-1967 Chevy Bel Air

2-Piece Rear Main Chevy 283

1968 Chevy Bel Air

Gen 1 L14 Small Block Chevy

1970-1975 Chevy Bel Air

2-Piece Rear Main Chevy 400

1958-1967 Chevy Biscayne

2-Piece Rear Main Chevy 283

1968 Chevy Biscayne

Gen 1 L14 Small Block Chevy

1970-1972 Chevy Biscayne

2-Piece Rear Main Chevy 400

1969-1973 Chevy Blazer

Gen 1 L14 Small Block Chevy

1958-1961 Chevy Brookwood

2-Piece Rear Main Chevy 283

1969 Chevy Brookwood

Gen 1 L14 Small Block Chevy

1970-1972 Chevy Brookwood

2-Piece Rear Main Chevy 400
Gen 1 L14 Small Block Chevy

1960-1967 Chevy C10

2-Piece Rear Main Chevy 283

1968-1973 Chevy C10

Gen 1 L14 Small Block Chevy

1976-1980 Chevy C10

2-Piece Rear Main Chevy 400

1960-1967 Chevy C10 Suburban

2-Piece Rear Main Chevy 283

1968-1973 Chevy C10 Suburban

Gen 1 L14 Small Block Chevy

1960-1967 Chevy C20

2-Piece Rear Main Chevy 283

1968-1973 Chevy C20

Gen 1 L14 Small Block Chevy

1976-1980 Chevy C20

2-Piece Rear Main Chevy 400

1960-1967 Chevy C20 Suburban

2-Piece Rear Main Chevy 283

1968-1973 Chevy C20 Suburban

Gen 1 L14 Small Block Chevy

1976-1980 Chevy C20 Suburban

2-Piece Rear Main Chevy 400

1960-1967 Chevy C30

2-Piece Rear Main Chevy 283

1968-1973 Chevy C30

Gen 1 L14 Small Block Chevy

1976-1979 Chevy C30

2-Piece Rear Main Chevy 400

1969-1973 Chevy Camaro

Gen 1 L14 Small Block Chevy

1966-1967 Chevy Caprice

2-Piece Rear Main Chevy 283

1968-1969 Chevy Caprice

Gen 1 L14 Small Block Chevy

1970-1973 Chevy Caprice

2-Piece Rear Main Chevy 400
Gen 1 L14 Small Block Chevy

1974-1976 Chevy Caprice

2-Piece Rear Main Chevy 400

1964-1967 Chevy Chevelle

2-Piece Rear Main Chevy 283

1968-1969 Chevy Chevelle

Gen 1 L14 Small Block Chevy

1970-1973 Chevy Chevelle

2-Piece Rear Main Chevy 400
Gen 1 L14 Small Block Chevy

1963-1967 Chevy Chevy II

2-Piece Rear Main Chevy 283

1968 Chevy Chevy II

Gen 1 L14 Small Block Chevy

1957-1961 Chevy Corvette

2-Piece Rear Main Chevy 283

1957-1958 Chevy Del Ray

2-Piece Rear Main Chevy 283

1959-1960 Chevy El Camino

2-Piece Rear Main Chevy 283

1964-1967 Chevy El Camino

2-Piece Rear Main Chevy 283

1968-1969 Chevy El Camino

Gen 1 L14 Small Block Chevy

1970-1973 Chevy El Camino

2-Piece Rear Main Chevy 400
Gen 1 L14 Small Block Chevy

1974-1976 Chevy El Camino

2-Piece Rear Main Chevy 400

1969 Chevy Estate

Gen 1 L14 Small Block Chevy

1970 Chevy Estate

2-Piece Rear Main Chevy 400
Gen 1 L14 Small Block Chevy

1976 Chevy G10

2-Piece Rear Main Chevy 400

1968-1973 Chevy G10 Van

Gen 1 L14 Small Block Chevy

1975-1980 Chevy G20

2-Piece Rear Main Chevy 400

1967 Chevy G20 Van

2-Piece Rear Main Chevy 283

1968-1973 Chevy G20 Van

Gen 1 L14 Small Block Chevy

1975-1980 Chevy G30

2-Piece Rear Main Chevy 400

1958-1967 Chevy Impala

2-Piece Rear Main Chevy 283

1968-1969 Chevy Impala

Gen 1 L14 Small Block Chevy

1970-1973 Chevy Impala

2-Piece Rear Main Chevy 400
Gen 1 L14 Small Block Chevy

1974-1976 Chevy Impala

2-Piece Rear Main Chevy 400

1960-1967 Chevy K10

2-Piece Rear Main Chevy 283

1968-1973 Chevy K10

Gen 1 L14 Small Block Chevy

1975-1980 Chevy K10

2-Piece Rear Main Chevy 400

1960-1967 Chevy K10 Suburban

2-Piece Rear Main Chevy 283

1968-1973 Chevy K10 Suburban

Gen 1 L14 Small Block Chevy

1975-1979 Chevy K10 Suburban

2-Piece Rear Main Chevy 400

1960-1967 Chevy K20

2-Piece Rear Main Chevy 283

1968-1973 Chevy K20

Gen 1 L14 Small Block Chevy

1975-1980 Chevy K20

2-Piece Rear Main Chevy 400

1967 Chevy K20 Panel

2-Piece Rear Main Chevy 283

1960-1967 Chevy K20 Suburban

2-Piece Rear Main Chevy 283

1968-1973 Chevy K20 Suburban

Gen 1 L14 Small Block Chevy

1975-1980 Chevy K20 Suburban

2-Piece Rear Main Chevy 400

1968-1973 Chevy K30

Gen 1 L14 Small Block Chevy

1977-1980 Chevy K30

2-Piece Rear Main Chevy 400

1975-1979 Chevy K5 Blazer

2-Piece Rear Main Chevy 400

1959-1961 Chevy Kingswood

2-Piece Rear Main Chevy 283

1969 Chevy Kingswood

Gen 1 L14 Small Block Chevy

1970-1972 Chevy Kingswood

2-Piece Rear Main Chevy 400
Gen 1 L14 Small Block Chevy

1973 Chevy Laguna

2-Piece Rear Main Chevy 400
Gen 1 L14 Small Block Chevy

1974-1976 Chevy Laguna

2-Piece Rear Main Chevy 400

1964-1967 Chevy Malibu

2-Piece Rear Main Chevy 283

1973 Chevy Malibu

2-Piece Rear Main Chevy 400
Gen 1 L14 Small Block Chevy

1974-1976 Chevy Malibu

2-Piece Rear Main Chevy 400

1970-1976 Chevy Monte Carlo

2-Piece Rear Main Chevy 400

1957-1961 Chevy Nomad

2-Piece Rear Main Chevy 283

1969-1973 Chevy Nova

Gen 1 L14 Small Block Chevy

1957 Chevy One-Fifty Series

2-Piece Rear Main Chevy 283

1976 Chevy P30

2-Piece Rear Main Chevy 400

1961-1962 Chevy P30 Series

2-Piece Rear Main Chevy 283

1968-1969 Chevy P30 Van

Gen 1 L14 Small Block Chevy

1973 Chevy P30 Van

Gen 1 L14 Small Block Chevy

1959-1961 Chevy Parkwood

2-Piece Rear Main Chevy 283

1957-1958 Chevy Sedan Delivery

2-Piece Rear Main Chevy 283

1960-1967 Chevy Suburban

2-Piece Rear Main Chevy 283

1969 Chevy Townsman

Gen 1 L14 Small Block Chevy

1970-1972 Chevy Townsman

2-Piece Rear Main Chevy 400
Gen 1 L14 Small Block Chevy

1957-1958 Chevy Truck

2-Piece Rear Main Chevy 283

1960 Chevy Truck

2-Piece Rear Main Chevy 283

1957 Chevy Two-Ten Series

2-Piece Rear Main Chevy 283

1958 Chevy Yeoman

2-Piece Rear Main Chevy 283

1966 GMC 1000

2-Piece Rear Main Chevy 283

1960 GMC 1000 Series

2-Piece Rear Main Chevy 283

1962-1965 GMC 1000 Series

2-Piece Rear Main Chevy 283

1960-1965 GMC 1500 Series

2-Piece Rear Main Chevy 283

1966 GMC 2500

2-Piece Rear Main Chevy 283

1960-1965 GMC 2500 Series

2-Piece Rear Main Chevy 283

1960-1966 GMC 3000

2-Piece Rear Main Chevy 283

1960-1966 GMC 3500

2-Piece Rear Main Chevy 283

1967 GMC C25/C2500 Pickup

2-Piece Rear Main Chevy 283

1968-1972 GMC C25/C2500 Pickup

Gen 1 L14 Small Block Chevy

1967 GMC C25/C2500 Suburban

2-Piece Rear Main Chevy 283

1968-1972 GMC C25/C2500 Suburban

Gen 1 L14 Small Block Chevy

1967 GMC C35/C3500 Pickup

2-Piece Rear Main Chevy 283

1968-1972 GMC C35/C3500 Pickup

Gen 1 L14 Small Block Chevy

1973-1974 GMC C35/C3500 Pickup

2-Piece Rear Main Chevy 400

1975-1978 GMC K15

2-Piece Rear Main Chevy 400

1975-1978 GMC K15 Suburban

2-Piece Rear Main Chevy 400

1967-1974 GMC K15/K1500 Pickup

2-Piece Rear Main Chevy 400

1967-1974 GMC K15/K1500 Suburban

2-Piece Rear Main Chevy 400

1979-1980 GMC K1500 Suburban

2-Piece Rear Main Chevy 400

1975-1978 GMC K25

2-Piece Rear Main Chevy 400

1975-1978 GMC K25 Suburban

2-Piece Rear Main Chevy 400

1967 GMC K25/K2500 Pickup

2-Piece Rear Main Chevy 283

1968-1972 GMC K25/K2500 Pickup

Gen 1 L14 Small Block Chevy

1973-1974 GMC K25/K2500 Pickup

2-Piece Rear Main Chevy 400

1967 GMC K25/K2500 Suburban

2-Piece Rear Main Chevy 283

1968-1972 GMC K25/K2500 Suburban

Gen 1 L14 Small Block Chevy

1973-1974 GMC K25/K2500 Suburban

2-Piece Rear Main Chevy 400

1979-1986 GMC K2500 Suburban

2-Piece Rear Main Chevy 400

1967 GMC K35/K3500 Pickup

2-Piece Rear Main Chevy 283

1968-1972 GMC K35/K3500 Pickup

Gen 1 L14 Small Block Chevy

1973-1974 GMC K35/K3500 Pickup

2-Piece Rear Main Chevy 400

1966 GMC P1000

2-Piece Rear Main Chevy 283

1973-1977 GMC Sprint

2-Piece Rear Main Chevy 400

1955-1966 GMC Suburban

2-Piece Rear Main Chevy 283

1967 GMC Suburban

Gen 1 L14 Small Block Chevy

1956-1960 GMC Truck

2-Piece Rear Main Chevy 283

1965-1966 Studebaker Commander

2-Piece Rear Main Chevy 283

1965-1966 Studebaker Cruiser

2-Piece Rear Main Chevy 283

1965-1966 Studebaker Daytona

2-Piece Rear Main Chevy 283

1966 Studebaker Wagonaire

2-Piece Rear Main Chevy 283