Holley’s New Gen V LT EFI Top-End Kits Pair Ultra Lo-Ram, 102mm Throttle Body & Injectors

Holley EFI has added a large group of new Top End Kits that bundle intake-manifold hardware, a Sniper EFI throttle body and matched injector choices into one package. For GM Gen V LT builders, the most interesting versions center on Holley’s Lo-Ram and Ultra Lo-Ram architecture with a 102mm throttle body and injector options ranging from 42 lb/hr to 120 lb/hr.

That matters because an LT airflow upgrade is rarely just an intake-manifold decision. The manifold, throttle-body opening, injector capacity, fuel system, engine speed, boost level and calibration all have to work together. A package that removes some of the parts-matching guesswork is useful, but the right kit still depends on the rest of the build.

What Holley is packaging for Gen V LT

Holley currently lists the Gen V LT Lo-Ram and Ultra Lo-Ram Top End Kits as new products. One representative package, part number 300-719BK-100K, combines the black Gen V LT Ultra Lo-Ram intake with port-injection rails, a 102mm Sniper EFI throttle body, 100 lb/hr high-impedance USCAR/EV6 injectors and the supporting throttle-cable/bracket hardware. Holley also lists 42 lb/hr and 120 lb/hr versions, along with natural-finish alternatives.

Holley’s full Top End Kit lineup makes the broader strategy clear: instead of forcing a builder to separately choose an intake, throttle body, injectors and supporting pieces, the company is offering pre-grouped combinations for several LS, LT, small-block Chevy and Ford applications.

Why the Ultra Lo-Ram is especially interesting on boosted LT combinations

Holley describes its Gen V LT Ultra Lo-Ram as a low-profile, front-feed intake designed around forced-induction applications. The manifold uses a 105mm throttle-body opening, is offered with port-injection provisions and high-volume -8AN fuel rails, and is intended for combinations making peak power in roughly the 7,000-8,000 rpm range depending on the application.

Packaging is another major part of the appeal. Holley says the Ultra Lo-Ram is only 0.97 inch taller than a factory LT1 manifold and specifically notes that it clears C7 Corvette cowls and hoods without modification. That does not mean every engine-bay combination is automatically bolt-in, especially once charge piping, accessory placement, sensors and custom inlet plumbing are considered, but it gives builders a useful starting point for a high-rpm boosted LT package.

Holley’s official 300-719BK product page also shows why the manifold can serve as more than a simple airflow upgrade: the port-injection version provides the hardware foundation for adding supplemental fuel upstream of the LT’s direct injectors.

102mm throttle body: useful, but only when the rest of the system can use it

A larger throttle body can reduce restriction when the inlet tract, manifold and engine airflow demand justify it, but throttle-body diameter by itself is not a horsepower guarantee. On a street-driven LT build, the calibration still has to manage airflow modeling, idle behavior, transient response and electronic-throttle behavior correctly. On a high-output boosted build, the inlet, compressor or supercharger, manifold and cylinder-head airflow all become part of the same restriction chain.

The practical takeaway is to spec the throttle body as part of the system rather than as an isolated “bigger is better” upgrade. A 102mm throttle body makes much more sense when the manifold opening and total airflow plan are designed around it.

42 vs. 100 vs. 120 lb/hr injectors: choose for the fuel plan, not the badge

The injector choices are where builders need to be especially careful. The correct injector size depends on fuel type, base and differential fuel pressure, duty-cycle target, expected horsepower, brake-specific fuel consumption, the amount of fuel still handled by the factory direct-injection system and how the port system is commanded. E85 or other high-ethanol blends generally require more fuel volume than gasoline for the same power level, so injector and pump headroom can disappear quickly as boost rises.

That is why the 120 lb/hr option is not automatically “better” than the 100 lb/hr version, and why the 42 lb/hr package can still be appropriate for a very different combination. Injector characterization, controller strategy and calibration quality matter as much as the number printed on the injector.

For flex-fuel builds, the ECU or controller also needs trustworthy ethanol-content data. SMG Speed Shop stocks the AEM Ethanol Content Flex Fuel Sensor Kit for applications where a compatible ethanol-content sensor is part of the fuel and calibration strategy. A sensor alone is not a complete fuel-system upgrade, but accurate fuel-content data is an important input when the tune is expected to adapt to changing ethanol percentage.

The tune is part of the hardware package

Modern LT combinations are data-driven. Before leaning on a new intake, supplemental port injection or larger throttle body, the calibration needs to be verified with real logs: commanded versus actual throttle, fuel pressure, injector behavior, air-fuel ratio or lambda, ignition timing, knock response, temperatures and the rest of the channels relevant to the combination.

For supported GM applications, the HP Tuners MPVI4 with Pro Feature Set is one of the key tools for calibration and data acquisition. We recently covered why that logging-and-calibration ecosystem matters in our HP Tuners direct OBD-II tuning update. The vehicle in that story is different, but the principle is the same: hardware changes are only as useful as the calibration and data validation behind them.

How we would plan a Gen V LT intake and fuel upgrade

Before ordering a top-end package, define the actual operating envelope. Is the car naturally aspirated or boosted? What rpm will it realistically see? What fuel will it run? Is the direct-injection system staying stock, being upgraded or being supplemented by port injection? What hood and inlet-routing constraints exist? Will the car need to behave cleanly in traffic, or is it a dedicated competition build?

Those answers determine whether a low-profile Ultra Lo-Ram, another manifold architecture, 42/100/120 lb/hr port injectors and a 102mm throttle body make sense together. They also determine how much pump capacity, controller capability and calibration work the finished combination needs.

If you are building an LT-powered Corvette, Camaro, Cadillac or swap and want help putting the airflow, fuel and calibration package together, SMG Speed Shop can help source the hardware while North Texas High Performance can help with eligible installation, tuning and build-planning work.

Important emissions note: Holley classifies the 300-719BK manifold as Emissions Code 3 and states that it is legal for sale and use only on uncontrolled, non-emissions-controlled vehicles. Always verify the exact part number, application and local/federal requirements before purchase or installation.

Ready to plan the supporting hardware? Start with the HP Tuners MPVI4 and AEM flex-fuel sensor kit, or contact SMG Speed Shop for help matching the intake, fuel and data-acquisition pieces to your combination.