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Fuel System — OBS Chevy/GMC Trucks

Pumps, filters & the famous Vortec spider injector. OEM, GM & aftermarket part numbers for 1988–1998 Chevy/GMC C/K 1500 & 2500. Always verify fitment for your exact year, engine & drivetrain before ordering.

⚠️ Verify before buying. Fitment varies by year, engine (4.3/5.0/5.7/7.4), and 2WD/4WD. These are reference numbers — confirm against your VIN/build before ordering.
1Fuel Pump (TBI, In-Tank)verifyDetails →
🛠 Fits: 1988-1995 C/K 1500 & 2500 (TBI gasoline engines)
Low-pressure in-tank electric pump for TBI trucks (9-13 psi)
E3621SAirtex (OEM)
Aftermarket: Delphi FE0115
📝 Replace the strainer sock and inspect the tank while it's dropped. Prime tip: cycle the key 2-3 times after a pump swap before cranking.
2Fuel Pump Module (Vortec, 1996-1997)verifyDetails →
🛠 Fits: 1996-1997 C/K 1500 & 2500 (Vortec)
High-pressure in-tank pump module for CSFI Vortec trucks (60+ psi)
E3622SAirtex (OEM)
📝 Vortec CSFI needs full pressure — a weak pump causes long cranks and lean codes before it dies outright. Test pressure at the rail: spec is roughly 60-66 psi key-on.
3Fuel Pump Module (1998)verifyDetails →
🛠 Fits: 1997-1998 C/K 1500 & 2500 (later style)
In-tank pump module assembly for late trucks
E3947MAirtex (OEM)
GM #: 19177242
📝 Late-97 production switched module styles — 96/early-97 trucks use E3622S instead. Match against your old unit or VIN build date.
4Fuel Filter (Inline)Details →
🛠 Fits: 1988-1998 C/K 1500 & 2500 (gasoline engines)
Inline fuel filter on the frame rail
GF481ACDelco (OEM)
Aftermarket: WIX 33481
📝 Cheap and often forgotten. On Vortec trucks a clogged filter mimics a dying fuel pump — change this first.
5Spider Injector Upgrade (CSFI → MFI)verifyDetails →
🛠 Fits: 1996-1998 C/K 1500 & 2500 (5.0L & 5.7L Vortec)
Updated multi-port (MFI) spider injector assembly replacing the failure-prone CSFI poppet unit
FJ10566Delphi (OEM)
📝 The factory CSFI poppets clog and stick — rough idle, misfires, hard hot starts. GM's own fix was this MFI-style spider; it's a direct bolt-in under the upper intake, no tuning needed. The 4.3L V6 uses a different assembly.

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