1922-1930 all H-D (Excl

1 INCH SHORTENED

52-57 45" FLATHEAD

Fitting threads type: OEM style 3/8-24 inverted flare

OEM style replacement for 17572-99 upper & 17573-99 lower covers

4" 2:1 Fat Shot System, Chrome Sadel/Seats 1922-1930 all H-D (Excl06 11 Dyna Famous proven tunable disc based performance. Add or subtract discs to optimize power and sound 1. 75" primaries flow into 2. 5" true collector for huge torque gains 3. 5" muffler body flares out to 4" 2. 5" performance core with 'pillow pack' insulation Supplied with discs, closed end cap and trim ring Include detailed instructions and all necessary mounting hardware Add 4 discs to increase horsepower, exhaust tone and flow Subtract 4