SBP 1999-2007 Chevrolet Silverado GMC Sierra LARGE Aluminum Coolant Expansion Tank Black Cap

Straightboost® Performance – Massive Coolant Expansion Tank for 1999–2007 GM Trucks

At Straightboost® Performance, we’re committed to engineering high-quality, innovative products for the automotive performance community.

We’re proud to introduce our Massive Coolant Expansion Tank, designed specifically for 1999–2007 GM truck models, including the Chevrolet Silverado. This tank is a direct fit replacement that works seamlessly with the OEM air-box, offering a perfect blend of form and function.

If you’re looking to upgrade your factory plastic tank for enhanced performance, durability, and a cleaner engine bay appearance, this is the solution for you.

Key Benefits

• Nearly double the capacity of the OEM plastic tank — helps maintain cooler operating temperatures and improves overall efficiency.

• 25% lighter than the factory tank.

• Fully TIG-welded aluminum construction for long-lasting strength and reliability.

• Works with OEM air-box—no modifications required.

• Coolant level sight tube for quick visual checks.

• Billet aluminum radiator cap available in 16 PSI (standard OEM), 28 PSI, or 36 PSI for high-performance applications.

• Billet aluminum inlet/outlet barbs for secure connections.

Specifications

• Brand: Straightboost®

• Material: Aluminum

• Finish: Natural Aluminum

• Radiator Cap: Anodized Black 16 PSI (standard)

• OEM Tank Capacity: 0.94 gal (3.57 L)

• Straightboost Tank Capacity: 1.63 gal (6.18 L)

  • 74% increase in capacity (+0.69 gal / +2.61 L)

• Dimensions:

  • Length: 10″ (254 mm)

  • Width: 6.0″ (115 mm)

  • Height (tall side): 7.0″ (203 mm)

  • Height (short side): 6.0″ (127 mm)

Additional Details

• May fit other GM vehicles using the same style expansion tank (contact us to confirm compatibility).

• Custom fitting options available — AN and ORB fittings can be added or repositioned upon request.

• Made to order in the USA — current production time: 1–2 weeks.

• Note: Light surface scratches may be present due to the manufacturing process.

• No coolant level sensor port.

• For off-road or race use only.