The 987 series sits a step up from Fox's more common 2.0 IFP shocks in one specific way: body diameter. At 2.5" instead of 2.0", there's more internal volume for oil and nitrogen, which translates into better heat management and less fade when a shock is working hard for extended periods, exactly the kind of use a heavy-duty GM truck sees when it's actually loaded or towing over rough terrain rather than just commuting.
This is the front shock in Fox's 2.5 IFP Performance Series for GM's 2500HD/3500HD platform, built for stock height up to a 2.5" lift. Like the rest of Fox's IFP lineup, the internal floating piston keeps shock oil separated from a pressurized nitrogen chamber, preventing the fluid aeration that causes cheaper shocks to feel inconsistent once they've heated up. The aluminum body resists corrosion, and valving is tuned specifically for this application rather than shared across unrelated vehicles.
Sold individually, order two for the front axle. This is a bolt-on shock using factory mounting points, no reservoir bracket or hose routing to plan for since this is the smooth-body version, not a remote-reservoir setup.
Confirm your lift height against Fox's specification for this exact part number before ordering. GM's HD truck platform has several nearly-identical-sounding Fox shocks in this same family differing mainly by length for different lift ranges, and the visual difference between them isn't always obvious until you're comparing them side by side.
