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Mufflers OEM Replacement

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Big Twin Flathead / Knucklehead / Panhead

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Big Twin Flathead / Knucklehead / Panhead

The Gasbox 1930 Twin Tube Mufflers

The Gasbox 1930 Twin Tube Mufflers

Top quality reproduction of the distinctive Twin Tube muffler as originally used on 1930 V-model Big Twins. Complete with its two clamps.

The GasBox 1934 Upsweep Mufflers

The GasBox 1934 Upsweep Mufflers

Nice reproduction of the 1934 only muffler with upswept tail section. Custom use on other models is possible provided they have the correct headpipe diameter.

The GasBox 1939 CHP Upsweep Mufflers

The GasBox 1939 CHP Upsweep Mufflers

Authentic reproduction of the special muffler for the California Highway Patrol (CHP) as introduced in 1939, with upswept tail section and spot-welded seam construction. Designed for rigid frame Big Twins for which a special hanger bracket is available, too, but can be Custom fitted to most models with 1-3/4" pipes.

The GasBox Fishtail Mufflers

The GasBox Fishtail Mufflers

Top quality reproduction of the fishtail muffler as originally used on Big Twins 1935-1940. The E/U version has the Y-pipe integral with the fishtail muffler.

The GasBox Fishtail Seamed Mufflers

The GasBox Fishtail Seamed Mufflers

Very authentic reproductions of the original mufflers with correct details like the spot-welded bottom seam, end cap beadings and pipe saddles. These are very hard to tell from the factory equipment and accepted by the AMCA on restored motorcycles.

The GasBox Rocket Fin Mufflers

The GasBox Rocket Fin Mufflers

Accurate reproductions of the original Rocket Style mufflers as used by the factory on 1941–1949 Big Twins. A must for correct restaurations.

The GasBox Rocket Fin Seamed Mufflers

The GasBox Rocket Fin Seamed Mufflers

Very authentic reproductions of the original mufflers with correct details like the spot-welded bottom seam. These are very hard to tell from the factory equipment and accepted by the AMCA on restored motorcycles.

Cigar Style Mufflers

Cigar Style Mufflers

The legendary »Cigar« muffler was standard equipment on all Big Twin models 1950-1964. This reproduction features exact dimensions as the original counterpart.

The GasBox Cigar Style Seamed Mufflers

The GasBox Cigar Style Seamed Mufflers

Very authentic reproductions of the original mufflers with correct details like the spot-welded bottom seam. These are very hard to tell from the factory equipment and accepted by the AMCA on restored motorcycles.