From Supertrapp website:
Automotive section
DESCRIPTION: MODEL# MSRP
4'' UNIVERSAL 18.5'', 2.0''ID BLACK 449-2018 $236.00
4'' UNIVERSAL 18.5',' 2.25''ID, BLACK 449-2218 $236.00
4'' UNIVERSAL 18.5'', 2.5''ID, BLACK 449-2518 $236.00
4" UNIVERSAL 18.5",1.75" ID BLACK 449-1718 $236.00
5" GLASSPACK: FOR 3.5" OD PIPE 549-3519 $278.00
5" UNIVERSAL 14 " SHORTY,3.5"ID,BLACK 549-3514 $278.00
5" UNIVERSAL 18.5", 2.5" ID BLACK 549-2519 $278.00
5" UNIVERSAL 18.5", 3" ID BLACK 549-3019 $278.00
4” Disc S/C Standard has a 3.5” body diameter which tapers out to a 4” opening. They are available in an 18.50” length. The 18.50” length is available with an ID of 1.75”(44.5mm), 2.00”(50.8mm), 2.25”(57.2mm) or 2.50”(63.5mm). Center pull clamp is sold separately.
Twelve, 4” discs, a Closed End Cap and all necessary mounting hardware is included with all 4” Disc S/C Standards.
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Also available in chrome, but of course the price is higher.
These are 17" long.
DESCRIPTION: MODEL# MSRP
4" UNIV. SC ELITE, CHROME, 1.75" INLET 428-1717 $350.00
4" UNIV. SC ELITE, CHROME, 2.00" INLET 428-2017 $350.00
4" UNIV. SC ELITE, CHROME, 2.25" INLET 428-2217 $350.00
5" UNIV. SC ELITE, CHROME, 2.50" INLET 528-2519 $484.00
Aluminum Racing Series Slip-Ons with a Brushed Aluminum Finish are available in a 12” length with a 1.50”(38.1mm), 1.75”(44.5mm), 2.00”(50.8mm) or 2.50”(63.5mm) inlet diameter (ID). All models include tri-brackets to weld on.
Select models include eight or twelve, 4” discs.
Aluminum Racing Series Slip-Ons with a Polished Aluminum Finish are available in a length with a 1.50”(38.1mm), 2.00”(50.8mm) or 2.50”(63.5mm) inlet diameter (ID). All models include tri-brackets to weld on.
Select models include eight or twelve, 4” discs.
Add 4” race discs to increase horsepower, exhaust tone and flow.
Subtract 4” race discs to reduce sound and increase low-end torque.
DESCRIPTION:
MODEL#
MSRP
4'' UNIV. 1.50''ID,1.75''CORE,ALUM,8DISC
412-15000
$226.00
4'' UNIV. 2''ID, 2.0''CORE, ALUM.,8DISC
422-20000
$257.00
4'' UNIV.1.75''ID,1.75'CORE, ALUM,8DISC
412-17500
$226.00
4" UNIV. 2.5"ID,2.5"CORE,POL.ALUM,12DISC
423-25000
$278.00
4" UNIV:2" ID, 2" CORE, POL.ALUM.,8DISC
423-20000
$278.00
4" UNIV:2.5"ID,2.5"CORE,ALUM,12DISC
422-25000
$257.00
4''UNIV1.5''ID,1.75"CORE,POL ALUM,8DISC
413-15000
$247.00