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SwingCase Silverado & Sierra Fitment 2026 — SC Codes, Bed Lengths, Install Notes

By Cole Briggs, Founder & Editor —

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SwingCase Codes for Silverado and Sierra

SwingCase model codes — Silverado and Sierra fitment (2019+)
CodeTruckSideBed LengthYearsNotes
SC100Silverado 1500 / Sierra 1500Driver (left)6'6" standard + 8' long bed2019–currentMost common code for Double Cab / Crew Cab standard
SC101Silverado 1500 / Sierra 1500Passenger (right)6'6" standard + 8' long bed2019–currentPair with SC100
SC103Silverado 1500 / Sierra 1500Driver (left)5'8" short bed2019–currentAlso fits Colorado / Canyon — see note below
SC104Silverado 1500 / Sierra 1500Passenger (right)5'8" short bed2019–currentPair with SC103
SC105GMC Sierra DenaliDriver (left)Standard bed2019–currentDenali-specific rail profile; passenger: use fitment tool

📅 Prices verified November 2026. Amazon prices change — click through for the current price. Buying through our link costs you nothing extra.

Identifying Your Bed Length

The most common ordering mistake on the Silverado/Sierra platform is ordering SC100/101 for a short-bed Crew Cab. The correct code depends on bed length, not cab type alone — and on the 2019+ Silverado, the same Crew Cab body is available with two different bed lengths.

Silverado/Sierra bed length by cab configuration
Cab ConfigurationTypical Bed LengthCorrect Code Group
Regular Cab8 ft (long bed)SC100 / SC101
Double Cab (Extended Cab)6'6" (standard bed)SC100 / SC101
Crew Cab — standard bed option6'6" (standard bed)SC100 / SC101
Crew Cab — short bed option5'8" (short bed)SC103 / SC104

To confirm your bed length: measure the inside of the bed from the tailgate (closed, inside face) to the front wall. 5\'8" = 68 inches. 6\'6" = 78 inches. 8 ft = 96 inches. Your window sticker or door jamb label also lists bed configuration (e.g. "Standard Bed" or "Short Box").

Silverado / Sierra HD (2500 / 3500) Fitment

The 2500HD and 3500HD Silverado and Sierra share a different platform from the 1500 (GMT900/K2XX architecture for HD trucks). The SC100–SC105 codes are confirmed for the 1500 T1 platform (2019+). For HD trucks:

  • Use UnderCover's fitment tool with your exact year, model (2500 or 3500), and bed length
  • The HD bed rail cap profile differs from the 1500 — do not assume 1500 codes transfer
  • Silverado 2500/3500 (2020+): fitment tool typically shows SC100/SC101 for standard bed but verify — UnderCover's own tool is the authoritative source

Sierra Denali — SC105 Notes

The Sierra Denali has a distinct bed rail cap profile compared to standard Sierra trim levels — the chrome/brushed cap finish involves a slightly different geometry where the rail meets the bed wall. UnderCover publishes SC105 as the confirmed driver-side code for 2019+ Sierra Denali standard bed.

For the passenger side, no confirmed universal Denali code has been published at time of writing. Use UnderCover's fitment tool with "GMC Sierra Denali" + your year and bed length to identify the correct passenger code before ordering.

Colorado and Canyon — SC103 / SC104 Shared Code

SC103 and SC104 are shared codes covering both the Silverado/Sierra short bed and the Chevrolet Colorado / GMC Canyon mid-size pickup. If you drive a Colorado or Canyon, these are the codes to order — no separate Colorado-specific page is needed. Verify your exact year and bed on UnderCover's fitment tool to confirm, as the mid-size bed has slightly different rail proportions.

Install Notes for Silverado / Sierra

Spray-in bedliner

The Silverado is commonly ordered from the factory with a spray-in bedliner option (GM's dealer-applied spray liner or aftermarket LINE-X/Rhino). If the liner covers the rail cap mounting area (inside top face of the bed wall), remove liner at the six screw locations with a rotary tool before drilling. Full install detail at How to Install the SwingCase.

Bracket tailgate clearance

For 2019+ Silverado/Sierra standard and short beds, the recommended rear mounting screw position is 6–8 inches from the inside face of the closed tailgate. Swing the case to full open before drilling any holes to confirm tailgate clearance — the 5\'8" short bed has less positioning margin than the 6\'6" standard bed.

Pre-2019 Silverado / Sierra

The 2014–2018 Silverado/Sierra (K2XX platform) and earlier models are not covered by SC100–SC105. Use UnderCover's fitment tool with your specific year and bed length. Pre-2014 (900/800 platform) trucks may not have a current code available — check availability on UnderCover's site directly.

Disclosure: When you buy through links on this page, we earn a small commission from Amazon at no extra cost to you. This funds our independent research. We never recommend a product because it pays more commission. Full disclosure →

Check SwingCase Silverado Price on Amazon →

📅 Prices verified November 2026. Amazon prices change — click through for the current price. Buying through our link costs you nothing extra.

Frequently Asked Questions

What SwingCase fits a 2022 Silverado 1500 Crew Cab short bed?
SC103 (driver side) and SC104 (passenger side). The 2022 Silverado 1500 Crew Cab comes with a 5'8" short bed — this is the SC103/104 code group. Do not order SC100/101, which are for the 6'6" standard bed. The short-bed Crew Cab is one of the highest-volume Silverado configurations and the most common source of code mix-ups.
Does the SwingCase fit pre-2019 Silverado and Sierra?
UnderCover's SC100–SC105 codes are confirmed for 2019-and-newer Silverado 1500 / GMC Sierra 1500 (5th generation, T1 platform). For 2014–2018 (K2XX platform) and older trucks, the bed rail geometry differs — use UnderCover's official fitment tool with your exact year, model, and bed length before ordering. Ordering a code confirmed only for 2019+ on an older truck risks a non-fitting bracket.
What is the difference between SC100 and SC103?
SC100 is the driver-side code for the 6'6" standard bed (and 8' long bed) on 2019+ Silverado/Sierra. SC103 is the driver-side code for the 5'8" short bed on the same generation. The bed rail geometry differs between the two bed lengths — the codes are not interchangeable. To identify your bed: measure from the inside face of the closed tailgate to the front bed wall, or check your window sticker / door jamb label which lists cab/bed configuration.
Does the SwingCase fit the GMC Sierra the same as the Silverado?
Yes. The Silverado and Sierra share the same bed architecture on the T1 platform (2019+). SC100, SC101, SC103, SC104, and SC105 apply to both the Chevrolet Silverado and GMC Sierra 1500 for the same years and bed lengths. The Sierra Denali has a dedicated driver-side code (SC105) due to a specific rail cap geometry; for the passenger side, use UnderCover's fitment tool.
Does SC103 also fit the Chevy Colorado or GMC Canyon?
Yes — SC103 and SC104 are shared codes that also fit the Chevy Colorado and GMC Canyon. If you drive a Colorado or Canyon, these are the correct codes. Verify your exact year and bed on UnderCover's fitment tool; the Colorado/Canyon mid-size bed has slightly different rail proportions from the Silverado short bed, but the SC103/104 bracket geometry covers both.
What SwingCase code fits a Sierra Denali?
SC105 is the confirmed driver-side code for the Sierra Denali (2019+). For the passenger side, UnderCover has not published a confirmed Denali-specific code — use the fitment tool with your exact year, bed length, and "Sierra Denali" to verify. The Denali rail cap has a slightly different profile from standard Sierra trim levels, which is why it has its own driver-side code.