Customer Appreciation Week 2026

Speedway Lake-Style Header Collector Muffler Inserts, 3.5 Inch

Customer Appreciation Week 2026

Speedway Lake-Style Header Collector Muffler Inserts, 3.5 Inch
Speedway Motors

|

#9303845

Speedway Lake-Style Header Collector Muffler Inserts, 3.5 Inch

  • These muffler inserts will tone down the noise of your lake-style headers
  • 6-sided louvered steel core is wrapped with high-temperature packing for long life
  • Glasspack design provides a period correct sound
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$120.99

/pair

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$134.99

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Product Summary

Universal Fit, 10.00" Overall Length, Steel, Natural

  • These muffler inserts will tone down the noise of your lake-style headers
  • 6-sided louvered steel core is wrapped with high-temperature packing for long life
  • Glasspack design provides a period correct sound
  • Large end is 3-5/16" OD to fit inside 3.5" lake-style headers
  • Sold in pairs
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Key Specs

MFG. Part #9303845
BrandSpeedway Motors
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Need To Know

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855.313.9176
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Speedway Motors 9303845 Details

Tone down your Lakes Headers with these muffler inserts. These inserts are designed to provide excellent sound control with or without fiberglass packing. Standard inserts feature a heavy-duty, 6-sided louvered steel core that is wrapped with high-temperature packing for long life.

  • Steel Construction
  • Natural Finish
  • Sold in pairs
  • 10" length
  • Outlet/larger end O.D.  is 3-5/16"

Note: May require drilling or welding depending on your configuration

CARB Warning

For race/ off road use or for use on pre-1966 vehicles.

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, or if installed in vehicles model-year 1965 or older; motorcycles model-year 1977 or older; or off-highway recreational vehicles (such as off-road motorcycles and all-terrain vehicles) model-year 1996 and older. 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.
CA Prop 65
CARB warning

Speedway Motors 9303845 Specifications

KEY SPECS
MFG. Part #9303845
BrandSpeedway Motors
GENERAL
Overall Length10.00"
Outside Diameter3.30"
Material TypeSteel
FinishNatural
Sold in QuantityPair

Ratings & Reviews

4.7

51 Reviews

Overall Assessment

Customers have consistently praised the product for its perfect fit, easy installation, quality build, and commendable reduction of sound level. The product has also been commended for its versatility, fitting various models such as the Hi Boy Headers and the Model T c cab street rod. Despite a solitary report of an insulation issue, the majority acclaim the product's sound quality, with a mellow yet powerful noise level. The product is appreciated over competitors for its subtle sound effect, specifically appreciated in various settings such as veteran shows and cruises. Minor dimensional mismatches were reported, but did not deter overall satisfaction. Scheduled specification updates are suggested. One customer faced compatibility issues with another product – an isolated occurrence. The product is described as a solution to exhaust noise problems, without compromising neighborhood peace. The product emerges as a worthwhile repeat purchase for most customers, desiring a classic Hot Rod sound. Overall, the product is greatly recommended for its functionality and aesthetic appeal.

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4.7

51 reviews

5

43

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Most Liked Positive Review

5.0

Excellent product !

These were the solution to my problem. I had to strap on some full length mufflers every time I wanted to start my flathead. Since I popped these in, I can start it anytime without waking up the neighborhood. I bought the lakes head kit from Speedway and these inserts pop right in with a few hammer taps. Someone reviewed that they don't quiet the sound so I checked it with a decibel meter. the open headers were 86 at idle and 109 revving to 3000 rpm. The full mufflers were at 80 and 102. The inserts from speedway were the same as the mufflers (80 and 102) In addition, I think the inserts give the engine a cool sound, especially when revved up. I would recommend these to anyone.

Most Liked Negative Review

1.0

Mine did not fit as advertised.

I tried to insert these into Speedway's 3.5 lakepipe kit for flatheads. Definitely a no go. Looking at the pictures on the computer, it appears the ones shipped are a hybrid between the 4" and the 3.5" insert. The pipe appears shorter and thicker than the one pictured for the 3.5. Cannot recommend for the advertised application.

Filter by Ratings

I would buy again

5.0

8 months ago

Speedy

Casey il.

Verified

Great product fits great

Would Recommend

Still has the sound of a hot rod

5.0

9 months ago

Brad

Rome, Georgia

Verified

Has the sound of an open header hot rod but honestly sounds cleaner now and toned down very little. Just enough honestly.

Would Recommend

Customer review image

Great Baffles!!

5.0

9 months ago

31 Rat Rod

Ingram, TX

Verified

Running straight lakester pipes and these baffles reduce the exhaust noise. Super easy installation!!

Would Recommend

Would repeat purchase without hesitation

5.0

a year ago

T-Bucket

Ohio

Verified

Inserts fit snuggly into exhaust pipe straight off the header. Nice throaty sound that still commands attention but doesn't hurt the eardrums like the open headers did. Roadster actually sounds better than open headers. My application didn't require any type of modifications; no welding, fasteners, etc.

Would Recommend

I can always rely on Speedway having the correct parts.

5.0

a year ago

Oldman

Stay safe!

Verified

Only Speedway had required parts for my Hot Rod.

Would Recommend

I get all my stuff from you.

5.0

a year ago

jimdandy

orem utah

Verified

it goes on my 1932 ford coupe

Would Recommend

perfect fit

5.0

a year ago

otis

hawaii

Verified

Slipped right into my lake-style headers and fit snug.

Would Recommend

Yes

5.0

a year ago

Hot Rod

Oregon

Verified

Everything was top notch

Would Recommend

Great product!

5.0

a year ago

John

Burbank, CA.

Verified

I was skeptical whether or not these would quiet the beast enough, but they sound great! Mellow at idle, nice throaty tone under acceleration.

Would Recommend

Great fit. Great price

5.0

a year ago

Nisstech

Indian trail nc

Verified

Very simple install. Snug fit and I'm sure the neighbors are as happy as I am. Highly recommend

Would Recommend

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Showing 10 of 51 reviews

Questions & Answers

8 Questions • 12 Answers

Will these inserts work with Sprint car style headers, with a 9 inch turnout tip?

by Jim

• 2 years ago

1 answer

View Answer

Which end goes into the header collector first? Is it the large flange end or the small end? Thank You

by Harry

• 8 years ago

5 answers

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Will these fit 9300550

by Celtiki66

• 9 years ago

1 answer

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Will these work in item #930-0570H

by Steve

• 9 years ago

1 answer

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How do they installed are they welded?

by Mark

• 10 years ago

1 answer

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Do these come pre assembled or do they need to be pressed on and tack welded by the purchaser? The pic shows pre assembled.

by Ronnie

• 10 years ago

1 answer

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Will these mufflers cause hot spots on my AHC coated headers and ruin or discolor the finish?

by Flathead ModelA

• 10 years ago

1 answer

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What are the outside diameters of the 2 larger OD's ? Hopefully fit inside part# 91013374 Meg. and spot weld in for secure and good appearance???

by Vonzipper

• 11 years ago

1 answer

View Answer

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