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by Porter Mufflers

Porter’s “Shorty Offset” Mufflers

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The Porter “Shorty Offset” Mufflers are for those replacing “turbo” mufflers with offset inlets and/or outlets commonly found on the 1960’s muscle-cars. They feature a 14″ body length and 20″ overall length so they will easily fit within the muffler pockets of cars initially equipped with oval mufflers while maintaining the original exhaust pipe routing.  The offset Porter Muffler offers two options for your offset needs, 11 degrees, and 17 degrees.  The offset Porter Muffler is handmade using heavy-duty 16 gauge aluminized tubing. The stainless steel Porter Muffler is handmade using heavy-duty 16 gauge, highly polished aircraft grade, 304 stainless tubing. Our uniquely designed interior chamber is fitted with a gapped steel spiral core and packed with stainless steel wool to channel the exhaust and make that distinctive Porter Muffler sound. To continue our tradition of quality, each Porter Muffler is handmade using only the best heavy gauge and high-quality steel products sourced in the U.S.A.

Picking The Correct Offset Mufflers– If you are currently using a flat, oval-style turbo muffler and cannot change the existing pipe routing to accommodate the straight Porter Mufflers, we do have “Shorty Offset” mufflers to replace them! Determine if you have an 11 Degree or 17 Degree muffler using this illustration. 

best hot rod muffler


Offset Degree 

Inlet/Outlet Diameter

Body Diameter

Part Number

Ceramic-Painted Blue





Stainless steel




Ceramic-Painted Blue 17 2.00 3.5 PM352001417
Stainless steel 17 2.00 3.5 SSPM352001417
Ceramic-Painted Blue 11 2.25 4.0 PM402251411
Stainless Steel 11 2.25 4.0 SSPM402251411
Ceramic-Painted Blue 17 2.25 4.0 PM402251417
Stainless Steel 17 2.25 4.0 SSPM402251417
Ceramic-Painted Blue 11 2.50 4.0 PM402501411
Stainless Steel 11 2.50 4.0 SSPM402501411
Ceramic-Painted Blue 17 2.50 4.0 PM402501417
Stainless-Steel 17 2.50 4.0 SSPM402501417
Ceramic-Painted Blue 11 3.00 4.0 PM403001411
Stainless-Steel 11 3.00 4.0 SSPM403001411
Ceramic-Painted Blue 17 3.00 4.0 PM403001417
Stainless-Steel 17 3.00 4.0 SSPM403001417


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