K 2500 Truck 4WD V8-305 5.0L VIN M SFI (1998)
Fluid - Differential: Fluid Type Specifications
Axle
Axle Lubricant (GM P/N 1052271 or SAE 80W-90 GL-5 Gear Lubricant).
Limited-Slip Differential Friction Modifier
Limited-Slip Differential Friction Modifier (GM P/N 1052358 or equivalent).