10 Best Fast Lsxrt Intake 2026

⚡ Quick Verdict

📋 How We Evaluated

Evaluation focused on build quality, runner or flange fitment specificity, and real-world performance claims tied to airflow and horsepower. Value considered what each kit includes, plus installation complexity for common LS swap and truck applications.

Amazon rating signals were limited due to absent rating data, so suitability relied on the provided feature details and application targeting.

Engine Fitment	LS7 applications
Throttle Body Support	Compatible with FAST Big Mouth 102mm and factory throttle bodies
Performance Claim	26+ rear-wheel horsepower on near stock 500 c.i. LS7 with Big Mouth 102mm
Extras	Integrated nitrous bungs

What We Found

The FAST LSXr 102mm Intake Manifold for LS7 (146202B) emphasizes proven airflow gains and street-ready integration. The polymer material aims for lighter weight and cooler operation compared with aluminum manifolds. A standout claim states that testing on a near-stock 500 c.i.

LS7 with a Big Mouth 102mm throttle body produced 26+ rear-wheel horsepower, which directly ties the manifold to measurable improvement. The manifold supports FAST Big Mouth throttle bodies and is listed as compatible with factory throttle bodies as well.

It also includes integrated nitrous bungs, which benefits performance users running staged systems and wanting clean manifold-based plumbing. Fitment is described as precise bolt-on while permitting factory accessories and OEM fuel/emission connections without adjustments or clearance issues.

The listing also cites CARB approval number D-279-8, which adds regulatory comfort for qualifying street builds. Overall, the combination of measured gains, nitrous provisions, and compatibility focus makes it the most complete LS7-oriented option here.

Who It’s For

This manifold best fits LS7 owners, especially those pairing a Big Mouth 102mm throttle body for maximum airflow. It suits street builds that need cooler intake temperatures for repeat pulls while maintaining factory accessory locations. The integrated nitrous bungs appeal to drivers running power-adder systems or planning for future upgrades.

Compatibility with factory throttle bodies also helps buyers stay closer to OEM drivability during early tuning phases. Because it targets LS7 specifically, it reduces risk of incorrect geometry compared with more generic 102mm listings. It remains ideal for builders who want measurable performance claims plus tidy fitment.

Kit Components	LSXr 102mm manifold plus 102mm Big Mouth billet throttle body
Target Heads	LS1/LS2/LS6 cathedral port heads
Runner Feature	Interchangeable intake runners for power band tuning
Finish	Black Lexar manifold with billet throttle body

What We Found

The FAST LSXr 102mm Intake Manifold plus 102mm Big Mouth Billet Throttle Body Kit bundles the induction path and throttle control into one upgrade. The kit targets GM LS engines with cathedral port heads, calling out GM 4.8, 5.3, 5.7, 6.0, and 6.2 applications with LS1/LS2/LS6.

A key standout involves improved throttle response, torque, and airflow, supported by the kit’s focus on matching induction components. The Lexar manifold uses advanced polymer materials to cool intake temperatures, aiming to increase airflow and engine efficiency while avoiding heat soak associated with cheaper aluminum intakes.

Interchangeable intake runners allow tuning the power band for different cam and exhaust combinations. It also lists a sleek black finish, a FAST logo, and an option for billet fuel rails, while the Big Mouth throttle body uses natural billet aluminum.

Fit type is vehicle specific, which helps avoid ad-hoc bracket or clearance fixes.

Who It’s For

This kit suits builders who want an out-of-the-box upgrade rather than piecing together a manifold and throttle body separately. It fits daily-drive street builds that benefit from improved throttle response and stable torque, plus weekend performance builds targeting higher rear-wheel numbers.

Cathedal-port LS owners benefit most, especially when planning runner-based power band tuning. The included throttle body reduces mismatch risk and streamlines installation planning. Value comes from buying coordinated components designed to work together, particularly for builds that prioritize intake charge cooling and airflow efficiency.

Target Engines	GM 4.8/5.3/6.0L port truck engines and LS1/LS2/LS6 race applications
Inlet Compatibility	Works with 90, 92, or 102mm throttle bodies
Design	Multi-layer modular with removable runners
Material	Advanced polymer for lightweight cooling performance

What We Found

The LSXrt 102mm Intake Manifold for GM 4.8/5.3/6.0L truck engines with cathedral port heads emphasizes platform fit and airflow. It uses a multi-layer modular design with removable runners, which supports easier disassembly and porting compared with non-serviceable cast designs.

A 102mm inlet works with 90, 92, or 102mm throttle bodies, aiming to reduce restriction across common build stages. The advanced polymer material is positioned to be lightweight and to cool intake charge for enhanced power and consistency.

The listing also calls out big gains in rear-wheel horsepower while retaining factory fitments and under-hood clearance. For truck builds, this focus on cowl clearance and correct engine targeting reduces the risk of buying an intake that does not physically fit.

Overall, it stands out as a practical performance upgrade that scales with throttle body selection.

Who It’s For

This option works best for owners of late-model GM port truck engines who want a 102mm manifold upgrade without extensive under-hood rework. It fits scenarios such as mild cam and exhaust packages where throttle body sizing may change during tuning.

The flexible 90/92/102mm inlet compatibility helps buyers stage upgrades over time. Removable runners benefit those planning porting or chasing drivability targets across RPM ranges. Value-focused buyers will also appreciate that the design targets factory clearance for easier installation.

Runner Design	Modular, removable runners for disassembly and porting
Air Inlet Size	102mm air inlet
Material	Advanced polymer for lighter weight and cooler operation
CARB Status	CARB-approved no. D-279-8

What We Found

The FAST LSXr 102mm Intake Manifold for LS1, LS2, and LS6 (146302B) uses a polymer build to cut weight versus aluminum and to run cooler during repeated pulls. Longer runners and a larger air inlet than stock aim to add horsepower without sacrificing low-RPM torque.

The modular, removable runner design supports easier disassembly, cleaning, and porting work when tuning a power band. A sleek black finish improves under-hood appearance, which helps it look cohesive on black-painted LS swaps. The manifold also lists CARB approval number D-279-8, a meaningful advantage for street builds.

Overall, it targets balanced street performance and serviceability for LS1/2/6 setups that need a 102mm intake path.

Who It’s For

This manifold suits LS1/LS2/LS6 owners who want a 102mm induction upgrade while retaining street manners. It fits best for drivers who value longer-runner torque characteristics and plan future porting or runner changes. The CARB approval helps buyers who want an easier path to registration for compliant builds.

It also suits installers who prefer a modular runner design for access during troubleshooting or accessory routing. Those seeking a complete throttle body package may need to buy throttle hardware separately.

Application	High HP runner set for LSXr 102mm LS3/L92 intake manifold
Port Family	Rectangle Port
Part Reference	Oem equivalent part number: N
Package Weight	1.934 kilograms

What We Found

The FAST High HP Runner Set for LSXr 102mm LS3/L92 intake manifold (146070) focuses on runner-level tuning for rectangle port applications. The listing names it as a high HP runner set and associates it directly with the LSXr 102mm LS3/L92 intake manifold.

It provides an OEM equivalent part number reference and detailed package dimensions and weight to support handling. While the provided information does not include runner length or flow numbers, the label implies a move toward higher-RPM efficiency compared with stock-style configurations.

This type of component benefits builders who already have the baseline manifold and want to reshape the power band without buying a different intake platform. It can also pair with cam changes where intake tuning becomes a larger part of total engine optimization.

Overall, it functions as a targeted upgrade path for refining performance rather than a complete intake replacement.

Who It’s For

This runner set suits builders who already own the compatible FAST LSXr 102mm LS3/L92 intake manifold and want to shift toward a high-power target. It fits applications such as bigger cam profiles, freer-flowing exhaust, and tuning work where runner geometry matters for volumetric efficiency.

It also suits dyno-tuners and enthusiasts who plan iterative experimentation to land on the right RPM range. Because the listing does not provide flow or runner geometry data, it works best for buyers comfortable verifying compatibility and selecting based on documented engine goals.

It is less suited for first-time buyers needing a complete intake system.

Kit Type	Billet fuel rail kit for LS engines
Rail Feature	Larger internal diameter for increased fuel volume
Performance Goal	Better fuel distribution and greater horsepower potential
Appearance	Show car quality appearance

What We Found

The COMP Cams Billet Fuel Rail Kit for LSXRT 102mm manifolds focuses on fuel delivery quality rather than intake air volume. It features billet fuel rails with larger internal diameter to provide increased fuel volume.

The intended result is improved fuel distribution, which can support greater horsepower potential when paired with appropriate injectors, pump upgrades, and calibration. The kit also positions itself as show-car quality, which matters to buyers who care about engine bay presentation.

Fit type is vehicle specific, and the kit targets LSXRT 4.8/5.3/6.0L plus LS1/LS2/LS6 combinations used with a 102mm manifold. While the listing supplies strong intentions for distribution and capacity, it does not include sensor port details or included hardware specifics in the provided information.

Overall, it serves as a useful supporting upgrade when building toward higher power levels that stress stock fuel rails and distribution.

Who It’s For

This fuel rail kit suits performance builders who already plan airflow upgrades with an LSXRT 102mm manifold and need fuel volume and distribution improvements. It fits engines approaching higher power where consistent rail pressure and even delivery matter, such as cam and turbo or high-flow NA builds.

The show-quality appearance appeals to customers who want a clean billet engine bay. It also suits owners who value vehicle-specific fitment to reduce bracket and line headaches. Buyers with mild upgrades may not need billet rails, especially if injector duty cycles and fuel system capacity remain within limits.

Fit Type	Vehicle Specific
Intake Size	102mm manifold
Country of Origin	United States
Package Weight	9.435 kilograms

What We Found

The FAST LSXr 102mm Intake Manifold for LS3/L92 appears positioned as a vehicle-specific upgrade with a straightforward packaging and logistics profile. The listing highlights fit type as vehicle specific, which helps reduce confusion for buyers who need the correct configuration for LS3/L92 applications.

It also provides package dimensions and weight, which can help plan shipping, receiving, and workspace layout during installation. While the provided key features do not include detailed polymer or runner specifications, the product naming and category placement still indicate an LSXr 102mm pathway.

The primary differentiator in the supplied information is the vehicle-specific intent, suggesting less trial-and-error during mounting. Buyers should validate port shape and any required throttle body flange matching against their exact cylinder head and throttle choice. As presented, it prioritizes correct application alignment more than feature explanation.

Who It’s For

This manifold suits LS3/L92 owners who want a 102mm intake option with vehicle-specific fitment. It best matches buyers who prefer selecting parts with direct application targeting rather than cross-referencing multiple runner or flange variants. The installation experience should feel simpler for correct-match head and throttle body setups.

It can also work for routine upgrades when a precise part number is important for keeping accessories aligned. Buyers who want detailed performance data or modular runner customization should verify those specs before purchase.

Material	CNC-machined nylon
Design	2PC interlocking clamp
MAP Sensor Compatibility	Aftermarket 3 bar sensors
Exclusion	Not compatible with factory GM 3 bar sensors

What We Found

The Fast LSXR/LSXRT 102 and BBK SSI intake manifold MAP sensor mount clamp uses a CNC-machined nylon, two-piece interlocking design. It specifically targets compatibility with FAST LSXR/LSXRT 102 and BBK SSI intake manifolds, which helps narrow installation variables for sensor mounting accuracy.

The purpose-built clamp aims to ensure proper MAP sensor placement and secure mounting on compatible manifolds. It also includes a compatibility limitation: it excludes factory GM 3 bar sensors and targets aftermarket 3 bar sensors.

A precision CNC nylon construction helps resist minor vibration and supports durability during engine heat cycles. The interlocking design provides stable retention, which matters for clean vacuum reference readings. Overall, this is a niche, fitment-critical accessory that can prevent sensor placement issues from turning into tuning problems or unstable readings.

Who It’s For

This clamp suits builders who use a MAP sensor mounted on a compatible FAST LSXR/LSXRT 102 or BBK SSI setup and need a reliable aftermarket 3 bar sensor mounting point. It fits troubleshooting scenarios where the sensor mount location or retention feels loose or misaligned.

The CNC nylon design benefits daily-driven builds by resisting heat and vibration while maintaining stable sensor positioning. It also suits those doing data-logging and calibration work who want accurate manifold pressure reference. Buyers using factory GM 3 bar sensors should avoid it, because the listing explicitly excludes that sensor type.

Compatibility	1999-2006 GM truck/SUV rails for 4.8L/5.3L/6.0L (except TBSS)
Required Action	Permanent modification to fuel rails
Injector Use	OEM Truck/SUV injectors only
Includes	Brackets for Flex Fuel and Non-Flex Fuel style injectors

What We Found

The FAST LSXRT OEM fuel rail mounting kit adapts 1999-2006 GM truck/SUV round plastic-style fuel rails to use with the FAST LSXRT intake manifold (Part #146602B). It provides OEM-style bracketry for 4.8L, 5.3L, and 6.0L engines, with an exception noted for TBSS.

The kit conversion requires permanent modification to the fuel rails, which means the original rails become unsuitable for returning to OEM LS truck intakes after the change. It also specifies use with OEM truck/SUV injectors, which helps define injector selection expectations.

For installation readiness, it includes brackets for flex fuel and non-flex fuel style injectors. This is a targeted solution for buyers who want to keep rail and injector strategies while upgrading intake manifolds for airflow. The key tradeoff is permanence, which influences long-term service planning and swap reversibility.

Who It’s For

FAST LSXRT OEM Fuel Rail Mounting Kit for 1999-2006 GM Truck/SUV Rails 4.8L 5.3L 6.0L Brac is best for shoppers who want a dependable match without overcomplicating the decision.

It is worth shortlisting if its size, feature set, warranty notes, and recent buyer feedback line up with the way you plan to use this Best Fast LSXRT intake.

Intake Type	LSXRT 102 mm throttle body flange manifold
Port Style	Rectangle Port, Multi Port
Material	Plastic, Black finish
Package Quantity	1

What We Found

The listing titled Intake Manifold, LSXRT, 102 mm Throttle Body Flange, Rectangle Port, Multi Port, Plastic, Black, GM LS-Series presents a flange and port-focused part configuration.

It clearly specifies a 102 mm throttle body flange and rectangle port, multi port style, which helps buyers verify compatibility with rectangle port head setups. The product uses plastic in a black finish, aligning with the common LSXRT theme of cooler-running polymer composites compared with aluminum.

However, the provided key features focus mainly on logistics, including package dimensions, quantity, and weight, rather than performance promises. That limitation matters because cylinder head pairing and runner geometry strongly affect real outcomes. Still, the explicit rectangle port and multi port descriptors make it useful for narrowing fitment.

Buyers should confirm exact throttle body flange bolt pattern requirements against their throttle body and intake sealing plan.

Who It’s For

This manifold suits rectangle port GM LS-series builds that need a 102mm throttle body flange and multi port configuration. It benefits hobbyists performing a swap who need clear port-shape targeting to prevent wrong-part purchases.

It can also work for custom setups where existing throttle body hardware already matches a 102mm flange standard. Because performance-specific details are not listed, it best matches buyers who prioritize correct port and flange geometry over proven horsepower claims.

Anyone planning to rely on advertised gains should verify compatibility and available tuning support.

What to Look For Before Buying

Choosing a Fast LSXRT intake starts with matching your LS engine family, port type, and throttle body size. Next, confirm heat management and material choice, since polymer designs aim to reduce intake charge temps. Consider included components like nitrous bungs, fuel rail mounts, and compatible sensor mounting.

Finally, prioritize CARB approval needs for street registration.

Check Match Port Style, Flange, and Throttle Body Size

Port style and flange geometry determine whether an intake bolts up correctly. Rectangle versus cathedral port heads often require different runner and manifold casting configurations. Many 102mm options also state compatibility with 90, 92, or 102mm throttle bodies, which can simplify staged builds.

Confirm bolt patterns, cowl clearance, and throttle linkage provisions before final purchase. When in doubt, cross-check your cylinder head model and your throttle body flange requirements.

Value Compare What the Kit Includes

Standalone manifolds typically require additional throttle body, wiring, and mounting hardware decisions. Bundled kits may cost more, but they reduce mismatch risk and streamline installation planning. Fuel rail kits and MAP sensor mounting accessories can add cost, yet they improve system completeness.

Evaluate whether missing items create hidden labor or parts costs. For value, choose the package level that matches the current stage of the build.

Rating Use Rating Signals Carefully, Then Rely on Fitment Detail

This review set lacks rating data for the provided listings, so feature targeting becomes the primary quality indicator. Look for clear application ranges, precise fitment notes, and explicit compatibility exclusions. Measurable performance claims, such as rear-wheel horsepower gains on a specified engine, add confidence.

When ratings exist, prioritize consistency across multiple similar products. For LS intakes, fitment clarity often predicts satisfaction more reliably than generic popularity.

Verify Confirm CARB Status and Installation Permanence

Street-driven builds should verify CARB approval numbers when available. Some fuel rail mounting kits require permanent rail modification, which limits reversibility later. Confirm accessory fitment statements, including factory emission connections and clearance claims. Also verify nitrous bungs or sensor mounts if using power adders or calibration-heavy setups.

Pre-install checks reduce returns and save time during tuning schedules.

Frequently Asked Questions

What makes a Fast LSXRT intake different from a standard LS intake manifold?

Fast LSXRT options typically use polymer or advanced composite materials to reduce intake heat soak. Many listings also focus on a 102mm inlet path and modular runner designs for tuning the power band. Some variants include nitrous bungs, sensor mount provisions, or throttle body compatibility notes that simplify build integration.

Specific differences depend on engine family and port type.

Which port type should be matched for LS cylinder heads?

Catalhedral port heads generally require cathedral port manifold configurations, while rectangle port heads need rectangle port manifolds. The correct runner and port shape prevent sealing issues and prevent airflow mismatches. Misidentifying port type can lead to additional parts, extended labor, or a full return.

Verifying the head casting and the manifold listing’s port description avoids those problems.

Do 102mm manifolds require a 102mm throttle body?

Not always. Some FAST LSXrt 102mm manifolds state compatibility with 90, 92, or 102mm throttle bodies. A larger throttle body can reduce restriction at higher airflow levels, but the best setup still depends on cam, converter, and calibration targets. Matching throttle sizing to planned power helps maintain response and drivability.

Are these intakes CARB approved for street use?

Some listings include CARB approval numbers such as D-279-8, which supports legal street registration in qualifying states. Other listings in this set do not mention CARB status, so legality must be verified for the specific product and application.

Buyers should confirm the CARB number matches their exact engine and intended use. Checking local requirements remains essential.

Will a MAP sensor mount clamp be necessary?

A clamp can become necessary when the manifold design requires a specific mounting solution for aftermarket MAP sensors. The listing for a CNC nylon interlocking clamp targets compatible FAST LSXR/LSXRT 102 or BBK SSI manifolds.

It also excludes factory GM 3 bar sensors, so sensor choice drives whether the clamp helps. If the MAP sensor mounts already align on the manifold, additional accessories may be unnecessary.

🎯 Final Verdict

Choose the FAST LSXr 102mm Intake Manifold for LS7 (146202B) as the top pick for cool-running polymer construction and a credible 26+ rear-wheel horsepower gain claim. It also integrates nitrous bungs and maintains factory accessory and fuel/emission connection fitment, making it a complete LS7-centric solution.

The runner-up, the LSXr 102mm Intake Manifold + 102mm Big Mouth Billet Throttle Body Kit, suits cathedral-port GM LS builds needing a coordinated throttle-and-manifold upgrade. Confirm port type and throttle flange compatibility, then order the matched kit.