EFI Fuel Tank Kit 400LPH Pump for LS and LT Swaps on 1968-1970 Pontiac GTO/Lemans
When adapting a modern LS or LT engine to a classic 1968 to 1970 Pontiac GTO or Lemans chassis the stock fuel system can struggle under higher flow demands. This EFI fuel tank kit integrates a 400 LPH Walbro pump directly into the original A Body tank to supply up to 550 hp engine conversions without cutting or welding. The internal mounting uses surrounding fuel to dissipate heat which prevents vapor lock during sustained high load driving sessions. An integrated sending unit maintains linear level readings even when running ethanol blends and vibration is high so false low warnings do not catch you off guard.
Efficient Internal Cooling to Prevent Vapor Lock
By placing the 400 LPH Walbro pump fully inside the original fuel tank, this design uses the surrounding liquid as a natural heat sink to keep the pump element cool under extreme demand. Continuous immersion eliminates the formation of vapor bubbles that can interrupt fuel delivery at sustained wide-open throttle. This method also curbs pump noise, since the tank walls act as a sound barrier, and it reduces aeration in the supply line for a smoother and more consistent flow to the injector rails. With the pump protected from air exposure, the risk of overheating or dry-running is virtually eliminated even during extended spirited driving. This approach ensures uninterrupted fuel pressure to support both sudden throttle bursts and long highway pulls.
Direct Fit Integration Preserving Factory Tank Structure
The kit mounts directly into 1968–1970 Pontiac GTO and Lemans A-Body tanks without requiring cutting or welding, reusing every stock mounting point and seal surface. This precision alignment maintains the integrity of the original vent and filler neck channels, so fuel and vapor routing remain unchanged. Installation calls for basic hand tools and supplied hardware, straps, gaskets, vent filter, and filler neck adapter to create a leak-free seal. By avoiding permanent modifications, owners can retain factory appearance and full reversibility of the tank. The entire process can be completed in a single afternoon, making it ideal for DIY enthusiasts and professional restorers alike.
Integrated Sending Unit for Accurate Level Monitoring
The built-in sending unit employs a precision resistor design that translates actual fuel volume into a linear electrical signal, delivering steady gauge readings regardless of ethanol content or road vibration. Its corrosion-resistant components stand up to modern bio-fuels and aggressive additives, ensuring long-term reliability. Unlike aftermarket float sets prone to erratic jumps, this unit smooths out reading fluctuations even on steep hills or during sudden acceleration. Drivers benefit from clear and consistent information about remaining range, avoiding unwelcome surprises during spirited runs or long trips. This attention to detail in level sensing complements the robust pump performance to provide a complete fuel management solution.
Robust 400 LPH Pump Capacity for Supercharged or High-Output Engines
Specifically rated to support supercharged applications and naturally aspirated engines producing more than 550 horsepower, the Walbro pump delivers a steady flow profile that meets the demands of aggressive tuning. Bench and in-tank testing confirm stable pressure output at high engine speeds, ensuring the air/fuel mixture never leans out under peak load. This capacity makes the unit suitable for forced-induction builds as well as high-rpm small-block swaps, providing a margin of safety for future power upgrades. By combining ample volume with reliable cooling and noise reduction, the pump becomes a foundation for any LS or LT conversion in a classic Pontiac A-Body chassis. Enthusiasts can tune with confidence, knowing the fuel supply will support every stage of performance enhancement.
Trust this MuscleRods design for consistent fuel delivery and for a smaller capacity fuel pump Kit at 255 LPH consider our 1968-1970 GTO / Lemans EFI Fuel Tank Kit - 255 LPH Pump.