1968 C3 Emissions Decal - B 327/427 AT 3927738 - OEM Number(s) (3927738)
This 1968 Emissions Control Decal – B restores an often-overlooked but factory-critical component of your Corvette’s underhood presentation. Found on all 1968 automatic transmission Corvettes equipped with either the 327ci/300hp small block or 427ci/390hp and 427ci/400hp big blocks, this label provided essential instructions for setting engine timing and carburetor idle speed to meet federal emissions and performance standards. Its placement evolved during the production run—appearing on the left-hand radiator top support in early builds, and later repositioned above the brake master cylinder. This exact reproduction matches original size, layout, and graphics for accurate concours-level detailing.
Features
• Correct for 1968 C3 with AT and 327/300hp, 427/390hp, or 427/400hp engines
• Label “B” emissions decal used during entire 1968 model year
• Instructs timing and idle adjustment for emissions compliance
• Early cars: mounts to top LH radiator support
• Later cars: mounts above brake master cylinder
• Approximate size: 1-1/2" x 5-5/8"
• Durable, high-contrast decal with factory-style print and adhesive backing
Tech Notes
Also referenced under GM part number 3927738
Because Details Matter
Factory emissions labels weren’t just bureaucratic tape—they offered real guidance for maintaining optimal performance. This correct 1968 decal adds credibility to your restoration while telling the story of evolving compliance requirements under the hood.
Also known under these part numbers: (For reference only)