Home / Shop / Flowmaster Super HP-2 409 Stainless Steel 2.5 Inch Muffler 12518409 Muffler, 2 1/2 in. Inlet/2 1/2 in. Outlet, Steel, Black, Each

Flowmaster Super HP-2 409 Stainless Steel 2.5 Inch Muffler 12518409 Muffler, 2 1/2 in. Inlet/2 1/2 in. Outlet, Steel, Black, Each

SKU: FLO12518409

Mufflers

Flowmaster

Flowmaster Super HP-2 409 Stainless Steel 2.5 Inch Muffler 12518409 Muffler, 2 1/2 in. Inlet/2 1/2 in. Outlet, Steel, Black, Each

SKU: FLO12518409

Mufflers

Special Order. Contact for ETA. This item is out of stock in our warehouse and partner distribution centres. In some cases, this may be due to not having live inventory feeds available for all suppliers. Please contact us before ordering if you need to meet a specific deadline.

We accept

Description

These Super HP-2 mufflers from Flowmaster are designed for use with street rods, customs, and sport trucks. They feature stainless steel construction with an internal, layered-laminar jet engine gas flow design that uses guided sound control with broadband sound cancellation for a mellow '50s tone. These mufflers support up to 400 HP, while delivering outstanding looks, durability, and sound control.

Part Type

Hushpower II Muffler - 2.50 In/Out 18L 409S

Data: v4.2 - Upd: 2026-10-16 04:09:19

Specifications

Product Attributes - Brand: Flowmaster
Product Attributes - Manufacturer's Part Number: 12518409
Product Attributes - Part Type: Mufflers
Product Attributes - Product Line: Flowmaster Super HP-2 Mufflers
Product Attributes - UPC: 700042030248
Product Attributes - Muffler Material: 409 stainless steel
Product Attributes - Inlet Diameter (in.): 2.50 in.
Product Attributes - Outlet Diameter (in.): 2.50 in.
Product Attributes - Inlet Quantity: 1
Product Attributes - Outlet Quantity: 1
Product Attributes - Electronic Valve: No
Product Attributes - Internal Construction: Perforated tube
Product Attributes - Inlet Location: Center
Product Attributes - Outlet Location: Center
Product Attributes - Case Shape: Oval
Product Attributes - Reversible: No
Product Attributes - Muffler Color: Black
Product Attributes - Case Exterior Length (in.): 18.00 in.
Product Attributes - Overall Length (in.): 24.00 in.
Product Attributes - Thickness (in.): 4.000
Product Attributes - Width (in.): 5.500 in.
Product Attributes - Outlet Style: Standard, without tip
Product Attributes - Remanufactured: No
Product Attributes - Quantity: Sold individually.
Product Attributes - Notes: T-409 stainless steel

Reference Information

Brand Name/s	Flowmaster
StreetFX SKU	flo12518409
SFX Item ID	4984133
Supplier Item Code	4984133
Manufacturer SKU	12518409
Manufacturer UPC	700042030248
Alternative References	FLM12518409, HP-2, Inlet/2

Compatibility

Application Data

Universal Yes

Application Notes	Super HP-2 Series Muffler; 2.5 in. Center Inlet/Outlet; Oval; 4 in. x 5 in. x 18 in.; 409 Stainless Steel, Not Direct Fit-Some Adaptation Required
Beginning Year	1959
CC	5272
CID	322
Drivetrain	RWD
Ending Year	1959
Engine Family	BUICK V8 GAS
Engine Size	5.3L/322
Engine Type	V8
Liter	5.3
Make	CHEVROLET
Model	BEL AIR
Region	USA
Submodel	BASE

Application Notes	2.50 Inlet 2.50 Outlet ; 2.50 Inlet 2.50 Outlet , 2.50 Inlet 2.50 Outlet
Beginning Year	1959
CC	4638
CID	283
Drivetrain	RWD
Ending Year	1964
Engine Family	Chevy small block Gen I
Engine Size	4.6L/283
Engine Type	V8
Liter	4.6
Make	CHEVROLET
Model	BEL AIR
Region	USA
Submodel	BASE

Application Notes	Super HP-2 Series Muffler; 2.5 in. Center Inlet/Outlet; Oval; 4 in. x 5 in. x 18 in.; 409 Stainless Steel, Not Direct Fit-Some Adaptation Required
Beginning Year	1959
CC	4638
CID	283
Drivetrain	RWD
Ending Year	1964
Engine Family	Chevy small block Gen I
Engine Size	4.6L/283
Engine Type	V8
Liter	4.6
Make	CHEVROLET
Model	BEL AIR
Region	USA
Submodel	BASE

Application Notes	2.50 Inlet 2.50 Outlet ; 2.50 Inlet 2.50 Outlet , 2.50 Inlet 2.50 Outlet
Beginning Year	1961
CC	5704
CID	348
Drivetrain	RWD
Ending Year	1961
Engine Family	CHEVY W-BIG BLOCK V8 GAS
Engine Size	5.7L/348
Engine Type	V8
Liter	5.7
Make	CHEVROLET
Model	BEL AIR
Region	USA
Submodel	BASE

Application Notes	Super HP-2 Series Muffler; 2.5 in. Center Inlet/Outlet; Oval; 4 in. x 5 in. x 18 in.; 409 Stainless Steel, Not Direct Fit-Some Adaptation Required
Beginning Year	1961
CC	6704
CID	409
Drivetrain	RWD
Ending Year	1964
Engine Family	CHEVY W-BIG BLOCK V8 GAS
Engine Size	6.7L/409
Engine Type	V8
Liter	6.7
Make	CHEVROLET
Model	BEL AIR
Region	USA
Submodel	BASE

Application Notes	2.50 Inlet 2.50 Outlet ; 2.50 Inlet 2.50 Outlet , 2.50 Inlet 2.50 Outlet
Beginning Year	1962
CC	5358
CID	327
Drivetrain	RWD
Ending Year	1962
Engine Family	Chevy small block Gen I
Engine Size	5.3L/327
Engine Type	V8
Liter	5.3
Make	CHEVROLET
Model	BEL AIR
Region	USA
Submodel	BASE

Application Notes	Super HP-2 Series Muffler; 2.5 in. Center Inlet/Outlet; Oval; 4 in. x 5 in. x 18 in.; 409 Stainless Steel, Not Direct Fit-Some Adaptation Required
Beginning Year	1963
CC	6997
CID	427
Drivetrain	RWD
Ending Year	1963
Engine Family	CHEVY W-BIG BLOCK V8 GAS
Engine Size	7.0L/427
Engine Type	V8
Liter	7.0
Make	CHEVROLET
Model	BEL AIR
Region	USA
Submodel	BASE

Application Notes	2.50 Inlet 2.50 Outlet ; 2.50 Inlet 2.50 Outlet , 2.50 Inlet 2.50 Outlet
Beginning Year	1959
CC	5704
CID	348
Drivetrain	RWD
Ending Year	1961
Engine Family	CHEVY W-BIG BLOCK V8 GAS
Engine Size	5.7L/348
Engine Type	V8
Liter	5.7
Make	CHEVROLET
Model	BISCAYNE
Region	USA
Submodel	BASE

Application Notes	2.50 Inlet 2.50 Outlet ; 2.50 Inlet 2.50 Outlet , 2.50 Inlet 2.50 Outlet
Beginning Year	1959
CC	4638
CID	283
Drivetrain	RWD
Ending Year	1964
Engine Family	Chevy small block Gen I
Engine Size	4.6L/283
Engine Type	V8
Liter	4.6
Make	CHEVROLET
Model	BISCAYNE
Region	USA
Submodel	BASE

Application Notes	Super HP-2 Series Muffler; 2.5 in. Center Inlet/Outlet; Oval; 4 in. x 5 in. x 18 in.; 409 Stainless Steel, Not Direct Fit-Some Adaptation Required
Beginning Year	1959
CC	4638
CID	283
Drivetrain	RWD
Ending Year	1964
Engine Family	Chevy small block Gen I
Engine Size	4.6L/283
Engine Type	V8
Liter	4.6
Make	CHEVROLET
Model	BISCAYNE
Region	USA
Submodel	BASE

Application Notes	Super HP-2 Series Muffler; 2.5 in. Center Inlet/Outlet; Oval; 4 in. x 5 in. x 18 in.; 409 Stainless Steel, Not Direct Fit-Some Adaptation Required
Beginning Year	1961
CC	6704
CID	409
Drivetrain	RWD
Ending Year	1961
Engine Family	CHEVY W-BIG BLOCK V8 GAS
Engine Size	6.7L/409
Engine Type	V8
Liter	6.7
Make	CHEVROLET
Model	BISCAYNE
Region	USA
Submodel	BASE

Application Notes	2.50 Inlet 2.50 Outlet ; 2.50 Inlet 2.50 Outlet , 2.50 Inlet 2.50 Outlet
Beginning Year	1961
CC	6704
CID	409
Drivetrain	RWD
Ending Year	1964
Engine Family	CHEVY W-BIG BLOCK V8 GAS
Engine Size	6.7L/409
Engine Type	V8
Liter	6.7
Make	CHEVROLET
Model	BISCAYNE
Region	USA
Submodel	BASE

Application Notes	2.50 Inlet 2.50 Outlet ; 2.50 Inlet 2.50 Outlet , 2.50 Inlet 2.50 Outlet
Beginning Year	1962
CC	5358
CID	327
Drivetrain	RWD
Ending Year	1964
Engine Family	Chevy small block Gen I
Engine Size	5.3L/327
Engine Type	V8
Liter	5.3
Make	CHEVROLET
Model	BISCAYNE
Region	USA
Submodel	BASE

Application Notes	2.50 Inlet 2.50 Outlet ; 2.50 Inlet 2.50 Outlet , 2.50 Inlet 2.50 Outlet
Beginning Year	1963
CC	6997
CID	427
Drivetrain	RWD
Ending Year	1963
Engine Family	CHEVY W-BIG BLOCK V8 GAS
Engine Size	7.0L/427
Engine Type	V8
Liter	7.0
Make	CHEVROLET
Model	BISCAYNE
Region	USA
Submodel	BASE

Application Notes	Super HP-2 Series Muffler; 2.5 in. Center Inlet/Outlet; Oval; 4 in. x 5 in. x 18 in.; 409 Stainless Steel, Not Direct Fit-Some Adaptation Required
Beginning Year	1963
CC	6997
CID	427
Drivetrain	RWD
Ending Year	1963
Engine Family	CHEVY W-BIG BLOCK V8 GAS
Engine Size	7.0L/427
Engine Type	V8
Liter	7.0
Make	CHEVROLET
Model	BISCAYNE
Region	USA
Submodel	BASE

Application Notes	2.50 Inlet 2.50 Outlet ; 2.50 Inlet 2.50 Outlet , 2.50 Inlet 2.50 Outlet
Beginning Year	1960
CID	283
Drivetrain	RWD
Ending Year	1960
Engine Family	Chevy small block Gen I
Engine Size	4.6L/283
Engine Type	V8
Liter	4.6
Make	CHEVROLET
Model	BISCAYNE
Region	USA
Submodel	FLEETMASTER

Application Notes	2.50 Inlet 2.50 Outlet ; 2.50 Inlet 2.50 Outlet , 2.50 Inlet 2.50 Outlet
Beginning Year	1960
CID	348
Drivetrain	RWD
Ending Year	1960
Engine Family	CHEVY W-BIG BLOCK V8 GAS
Engine Size	5.7L/348
Engine Type	V8
Liter	5.7
Make	CHEVROLET
Model	BISCAYNE
Region	USA
Submodel	FLEETMASTER

Application Notes	2.50 Inlet 2.50 Outlet ; 2.50 Inlet 2.50 Outlet , 2.50 Inlet 2.50 Outlet
Beginning Year	1959
CC	5704
CID	348
Drivetrain	RWD
Ending Year	1961
Engine Family	CHEVY W-BIG BLOCK V8 GAS
Engine Size	5.7L/348
Engine Type	V8
Liter	5.7
Make	CHEVROLET
Model	IMPALA
Region	USA
Submodel	BASE

Application Notes	2.50 Inlet 2.50 Outlet ; 2.50 Inlet 2.50 Outlet , 2.50 Inlet 2.50 Outlet
Beginning Year	1959
CC	4638
CID	283
Drivetrain	RWD
Ending Year	1964
Engine Family	Chevy small block Gen I
Engine Size	4.6L/283
Engine Type	V8
Liter	4.6
Make	CHEVROLET
Model	IMPALA
Region	USA
Submodel	BASE

Application Notes	Super HP-2 Series Muffler; 2.5 in. Center Inlet/Outlet; Oval; 4 in. x 5 in. x 18 in.; 409 Stainless Steel, Not Direct Fit-Some Adaptation Required
Beginning Year	1959
CC	4638
CID	283
Drivetrain	RWD
Ending Year	1964
Engine Family	Chevy small block Gen I
Engine Size	4.6L/283
Engine Type	V8
Liter	4.6
Make	CHEVROLET
Model	IMPALA
Region	USA
Submodel	BASE

Application Notes	2.50 Inlet 2.50 Outlet ; 2.50 Inlet 2.50 Outlet , 2.50 Inlet 2.50 Outlet
Beginning Year	1961
CC	6704
CID	409
Drivetrain	RWD
Ending Year	1964
Engine Family	CHEVY W-BIG BLOCK V8 GAS
Engine Size	6.7L/409
Engine Type	V8
Liter	6.7
Make	CHEVROLET
Model	IMPALA
Region	USA
Submodel	BASE

Application Notes	Super HP-2 Series Muffler; 2.5 in. Center Inlet/Outlet; Oval; 4 in. x 5 in. x 18 in.; 409 Stainless Steel, Not Direct Fit-Some Adaptation Required
Beginning Year	1961
CC	6704
CID	409
Drivetrain	RWD
Ending Year	1964
Engine Family	CHEVY W-BIG BLOCK V8 GAS
Engine Size	6.7L/409
Engine Type	V8
Liter	6.7
Make	CHEVROLET
Model	IMPALA
Region	USA
Submodel	BASE

Application Notes	2.50 Inlet 2.50 Outlet ; 2.50 Inlet 2.50 Outlet , 2.50 Inlet 2.50 Outlet
Beginning Year	1962
CC	5358
CID	327
Drivetrain	RWD
Ending Year	1964
Engine Family	Chevy small block Gen I
Engine Size	5.3L/327
Engine Type	V8
Liter	5.3
Make	CHEVROLET
Model	IMPALA
Region	USA
Submodel	BASE

Application Notes	2.50 Inlet 2.50 Outlet ; 2.50 Inlet 2.50 Outlet , 2.50 Inlet 2.50 Outlet
Beginning Year	1963
CC	6997
CID	427
Drivetrain	RWD
Ending Year	1963
Engine Family	CHEVY W-BIG BLOCK V8 GAS
Engine Size	7.0L/427
Engine Type	V8
Liter	7.0
Make	CHEVROLET
Model	IMPALA
Region	USA
Submodel	BASE

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Flowmaster Super HP-2 409 Stainless Steel 2.5 Inch Muffler 12518409 Muffler, 2 1/2 in. Inlet/2 1/2 in. Outlet, Steel, Black, Each

Flowmaster Super HP-2 409 Stainless Steel 2.5 Inch Muffler 12518409 Muffler, 2 1/2 in. Inlet/2 1/2 in. Outlet, Steel, Black, Each

Description

Part Type

Specifications

Reference Information

Compatibility

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