Trucks have been a great starting place for restoration and modification projects. Many automotive brands have offered models over the last 70 years with differing chassis, engine, and drive combinations. If you’re looking for a low-cost option with a healthy aftermarket and restoration availability, you may find the 1997 – 2003 General Motors 1500 series trucks to be a perfect fit for your needs. During restoration, it’s incredibly important to consider replacing or upgrading your GM 1500 Series fuel pump.

Choosing the Low-Cost Budget Truck

Both Chevrolet and GMC half-ton truck lines have multiple trim levels available, different engine and transmission options, and come available in both 2WD and 4WD. There is something for everyone.

This model featured the LS-engine family that started a new revolution that saw these engines swapped into everything. Most restoration projects will choose the V8 models or swap one of them in though.

The 4.8-liter V8 (producing 255 horsepower and 285 pound-feet of torque), the 5.3-liter V8 (producing 270 horsepower and 315 pound-feet of torque), and the 6.0-liter V8 (producing 300 horsepower and 355 pound-feet of torque) were available as options from General Motors, and all three have immense potential for restoration or modification.

Assuming the truck runs and drives, one area of focus should be the fuel system. The truck could have sat at some point in its life, or it could have been a constant workhorse and now have a few hundred thousand miles on the odometer.

Whatever the case may be, the fuel pump and other fuel system components may be on their last legs. If you have concerns with either, now is the time to address them. A new fuel system is key for the next phase of the truck’s life.

Replacing the 1999 – 2003 Chevy & GMC 1500 Series Fuel Pump Assembly

Replacing the fuel pump or the complete fuel pump assembly on the 1500 series trucks isn’t a complicated process. Once the fuel tank is removed from the vehicle, the fuel pump assembly can be taken out from the top side of the tank with simple hand tools.

Some will simply replace the pump assembly with an OEM drop-in replacement, however, keeping the factory design will keep inherent design problems going forward. The factory design uses a problematic venturi design to keep the canister full during hard cornering.

If you plan to build a corner carving truck for autocross, keeping this design will have limitations. The venturi design was used in all 1995 – 2005 GM trucks, vans, and SUVs, which will only allow for OEM-style fuel pumps with limited fuel flow potential.

Combating OEM Design Limitations

If you plan to add more horsepower to your truck, the OEM fuel pump won’t flow enough fuel for a lot more power than the factory level. You can add a larger fuel pump for more flow. Doing so requires the fuel pump assembly to be modified by cutting windows into the sides of the bucket.

This completely disables the venturi function of the OEM housing and the ability of the canister to stay full during cornering or acceleration. It will eventually lead to fuel starvation and overheating of the fuel pump.

Fixing the poor venturi design and adding a larger fuel pump can be achieved by switching over to Quantum’s QFS-A81HV 340LPH (340 liters per hour) drop-in fuel pump assembly. This assembly was designed specifically for the 1999 – 2003 Chevy and GMC 1500 Series trucks to eliminate the problematic venturi canister design found in all 1995 – 2005 GM trucks, vans, and SUVs while offering significantly more fuel flow for larger engines or forced induction applications.

This clean sheet design also allows the fuel tank to be run down to empty as the OEM fuel assembly does.

The assembly uses Ethanol safe PTFE / Teflon corrugated flex hose and Teflon-coated wiring throughout. They are 100% gasoline and E85 compatible. The new design features an updated 40-amp bulkhead connector to handle the additional amperage load of the high-volume pump, plus includes a new float arm, sending unit, tank seal, and 4-way wiring connector.

All QFS products come with a lifetime warranty. There’s no need to worry about paying for a replacement later.

Replacing Just The Fuel Pump

If you aren’t ready for a new complete assembly, you may just need to change the fuel pump only. A previous owner may have replaced or upgraded the assembly. In this case, you just need to add a new pump to meet your goals.

That’s an easy fix with Quantum’s varying selection of performance fuel pumps. Each pump in the line-up offers a different fuel flow to meet your horsepower goals. Check out the chart below to see which pump is rated at the horsepower level you need.

The chart uses the standard of 2.64 horsepower per LPH as the conversion criteria.

Part number	part description	horsepower support
QFS-A81HV	340LPH INTANK FUEL PUMP ASSEMBLY	897
HFP-367	165LPH INTANK OEM REPLACEMENT FUEL PUMP	435
HFP-603	190 LPH UNIVERSAL EXTERNAL INLINE PUMP	501
HFP-342	255LPH PERFORMANCE INTANK FUEL PUMP	673
QFS-342FT	340LPH E85/FLEX IN-TANK EFI PERFORMANCE FUEL PUMP	897
QFS-343FT	340LPH E85 INTANK FUEL PUMP	897
QFS-606FT	380LPH INLINE EXTERNAL E85 COMPATIBLE FUEL PUMP	1000

We Are Standing By For Your Order

If you plan to build or simply restore a 1999 – 2003 Chevy or GMC 1500 series truck, take the time to get the fuel system up to snuff. It’s most likely 20 years old, and if it was a previous work truck, it may not have been well maintained. The OEM design works well for simple replacement, but if you plan to modify your truck it will need a better fuel system.

You can order a better-designed replacement pump or complete assembly from Quantum Fuel Systems, Monday through Friday, 8:00 a.m. to 5:00 p.m. PT, over the phone or browse our extensive catalog. Be sure to contact us via our support page for any detailed technical questions, and we’ll get back to you as soon as possible.