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, engines, and drive combinations. The 1997 – 2003 General Motors 1500 series trucks are the perfect starting point for restoration projects. The aftermarket availability and price point for these trucks are unmatched. During restoration, it’s incredibly important to consider a fuel pump upgrade for your GM 1500 Series fuel pump.
If you’ve got your eyes on an older GM truck such as a 1973 – 1987 square body, you’ll want to check out our LS Swap Fuel System for Square Body Trucks guide.
Choosing the Low-Cost Budget Truck
Both Chevrolet and GMC half-ton truck lines have multiple trim levels available. They come in a variety of engine sizes, as well as transmission options to suit your needs. You can also find them in both 2WD and 4WD.
These trucks featured the LS-engine family that started a new revolution that saw these engines swapped into everything. Most restoration projects will opt for the original V8 or swap for one of the newer LS engines.
These are the engines that were available when these trucks first hit the market:
- 4.8-liter V8 (producing 255 horsepower and 285 pound-feet of torque)
- 5.3-liter V8 (producing 270 horsepower and 315 pound-feet of torque)
- 6.0-liter V8 (producing 300 horsepower and 355 pound-feet of torque)
Assuming the truck runs and drives, one area of focus should be the fuel system. It’s likely that the truck will still have it’s original fuel pump and it’s been sitting for a long period.
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.
Fuel Pump Upgrade for 1999 – 2003 Chevy & GMC 1500 Series
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 do a fuel pump upgrade by adding a larger fuel pump for more flow. Doing so requires a modification to the fuel pump assembly. You’ll need to cut windows into the sides of the assembly 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. We have a better solution.
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.
340LPH Drop In Fuel Pump Assembly for Chevy & GMC Trucks, QFS-A81HV
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. The chart below lists our available fuel pumps that are compatible with 1500 series trucks and the amount of horsepower they support.
The chart uses the standard of 2.64 horsepower per LPH as the conversion criteria.
| Part number | part description | horsepower support |
|---|---|---|
| QFS-A81HV | 340LPH IN TANK FUEL PUMP ASSEMBLY | 897 |
| HFP-367 | 165LPH IN TANK OEM REPLACEMENT FUEL PUMP | 435 |
| HFP-603 | 190 LPH IN LINE UNIVERSAL PUMP | 501 |
| HFP-342 | 255LPH IN TANK PERFORMANCE FUEL PUMP | 673 |
| QFS-342FT | 340LPH IN TANK PERFORMANCE FUEL PUMP | 897 |
| QFS-343FT | 340LPH IN TANK PERFORMANCE FUEL PUMP | 897 |
| QFS-606FT | 380LPH IN LINE E85 COMPATIBLE PERFORMANCE FUEL PUMP | 1000 |
We Are Standing By For Your Order
If you plan to build or simply restore a 1997 – 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 could have missed regular maintenance routines earlier in it’s life. The OEM design works well for simple replacement, but if you plan to modify your truck it will need a better fuel system.
