How to Confirm an Aftermarket Fuel Tank Fits Your Application Finding the correct aftermarket fuel tank replacement requires precise measurements and configuration details unique to your truck. Follow these steps carefully to ensure proper fitment and compatibility before purchasing. Step 1: Know Your Truck's Year, Make, Model & OEM Part Number Start by identifying your truck's year, make, model, and OEM part number for the fuel tank. Having your factory part number ready is the most reliable starting point for confirming you are ordering the correct aftermarket replacement fuel tank for your specific application. However, please be aware that in the aftermarket parts industry, OEM part number databases are not always complete or fully up to date. Because of this, we rely on a series of specific vehicle and tank details to accurately determine the correct replacement part — even when a direct OEM part number cross is unavailable. Please note: As an aftermarket truck parts supplier, we do not have access to VIN-based lookup systems and are unable to cross-reference OEM part numbers on your behalf. The fitment steps below are designed to help us identify the correct fuel tank for your application without requiring an exact OEM part number match. Step 2: Confirm Your Fuel Type Identify whether your truck runs on diesel fuel or gasoline. Fuel tanks are not interchangeable between fuel types, and selecting the wrong tank can result in serious compatibility and safety issues. Step 3: Identify Your Fuel Tank Mounting Location Confirm the exact mounting location of the fuel tank being replaced on your truck. Aftermarket replacement fuel tanks are position-specific and are not interchangeable between mounting locations. Select the option that matches your application: Driver Side (Left Side) — Tank is mounted on the left side of the truck frame rail Passenger Side (Right Side) — Tank is mounted on the right side of the truck frame rail Inside Frame Mount — Tank is mounted inside the frame rails of the truck Please note: Many heavy duty trucks are equipped with fuel tanks on both sides of the frame. If you are replacing both tanks, each side will need to be ordered and confirmed separately, as driver side and passenger side tanks are often mirrored and not identical. Step 4: Identify Your Fuel Tank Shape & Type Aftermarket replacement fuel tanks are available in several distinct shapes. Confirm which tank type matches your current application: D-Tank – A D-shaped tank that mounts flush along the frame rail Rectangle Tank – A standard rectangular-shaped fuel tank Round Tank – A cylindrical round fuel tank Step 4A: Dimensions for D-Tanks & Rectangle Tanks If your truck uses a D-Tank or Rectangle Tank, provide the following three measurements for an accurate fitment match: Length Height Width Step 4B: Dimensions for Round Tanks If your truck uses a Round Tank, provide the following two measurements: Length — clarify if you are measuring seam to seam or overall end to end Diameter — the outside diameter of the tank measured in the middle at the ends from top to bottom Step 5: Confirm the Fuel Fill Cap Location Standing outside the truck and looking directly at the tank, confirm where the fuel fill cap is located: Right Hand (RH) Fill — fill cap on the right side as you face the tank Left Hand (LH) Fill — fill cap on the left side as you face the tank Center Fill — fill cap centered on the tank Incorrect fill cap location will prevent proper hose and cap alignment on your truck. Step 6: Confirm Whether Steps Are Built Into the Tank Many fuel tanks include integrated cab access steps built directly into the tank body. Confirm whether your original tank includes steps, as this is a critical detail that affects both fitment and function. Step 7: For D-Tanks — Confirm Your Step Configuration If you are replacing a D-Tank with steps, you will need to confirm one of the following step configurations: Steps on Tank Strap — the step is mounted to the tank strap rather than the tank body itself Step Brackets Built Into the Tank — the step mounting brackets are integrated directly into the tank structure This distinction is essential for ensuring your replacement tank installs correctly without requiring additional modification or hardware.
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