Granatelli GM LS3 6.2L Drive-By-Wire Billet Throttle Body – GMTBLS3

Granatelli Motor Sports 103mm RACE Throttle Body – LSX Drive-By-Wire

SKU: GMTBLS3

LS3 Throttle Body Upgrade: 103mm Billet Drive-By-Wire

Shopping for an LS3 102mm throttle body? 102mm is one of the most common aftermarket LS sizes. The Granatelli GMTBLS3 goes one step further with a 103mm bore, CNC-machined from 6061-T6 billet aluminum, in a complete drive-by-wire assembly that plugs into the GM 6-pin connector. It works with factory or aftermarket intake manifolds and is listed for the LS3 along with the LS1, LS2, LS6, LS7, LS9, LSA, LSX, LQ4 and LQ9.

TUNE REQUIRED

Trailblazer SS owners must call before ordering for proper calibration.

Built for serious LSX performance, the Granatelli 103mm RACE Throttle Body is CNC-machined from high-grade 6061-T6 billet aluminum to deliver massive airflow and throttle response gains. Designed for both naturally aspirated and forced induction builds, this throttle body is ideal for street and strip setups alike.

Key Features:

• 103mm Bore: Dramatically increases airflow over stock throttle bodies

• Boost-Ready: Handles up to 35 lbs of boost (draw-through or blow-through)

• Enhanced Acceleration: Improves engine response and driveability across the RPM range

• Direct Fit: No need to transfer parts—bolts on easily using a GM 6-pin connector

• Flexible Fitment: Works with factory or aftermarket intake manifolds

• Built to Last: CNC-machined from 6061-T6 billet aluminum for strength and durability

• Designed for LSX Engines: Compatible with LS1, LS2, LS3, LS6, LS7, LS9, LSA, LSX, LQ4 & LQ9

Important Notes:

• TUNE REQUIRED

• Trailblazer SS applications require calibration – please call before ordering

Key Features & Benefits

• Application-focused Granatelli Motor Sports design
• Built for dependable performance and service
• Designed for enthusiasts, professional installers, and performance builds

Fitment & Installation

Confirm the part number, vehicle or engine application, dimensions, and supporting components before installation. Modified vehicles may require additional clearance, fabrication, calibration, or related hardware depending on the combination.

102mm vs. 103mm vs. 108mm: Choosing an LS3 Throttle Body

• 103mm billet – GMTBLS3 (this page): the usual pick for a stock-style or boosted LS3 intake. Also available in black (GMTBLS3B). Boost-ready to 35 lbs, draw-through or blow-through.
• 108mm black billet – GMTBLS108B: for LS3, LSA and LSX builds that need more airflow than a 102mm or 103mm throttle body can deliver, and have a manifold that can use it.

Pick by your intake manifold opening, connector and boost level, not by the biggest number. Our LS, LT and HEMI throttle body size guide walks through every option.

Installation Notes

• Complete assembly. Nothing transfers from your factory throttle body.
• Plugs into the GM 6-pin drive-by-wire connector. Never force a plug or assume a look-alike adapter is correct.
• Check that your intake tube and coupler fit the larger inlet.
• A tune is required. Trailblazer SS owners must call before ordering for proper calibration.

LS3 Throttle Body FAQ

Will a 102mm or 103mm throttle body fit an LS3 intake?
The GMTBLS3 is listed for the LS3 and works with factory or aftermarket intake manifolds that use the GM 6-pin drive-by-wire setup. On a stock-style LS3 intake, a 103mm is the usual choice. Verify your manifold opening and bolt pattern before ordering.

Is a 103mm throttle body good for a boosted LS3?
Yes. It handles up to 35 lbs of boost in draw-through or blow-through setups.

Do I need a tune for an LS3 throttle body upgrade?
Yes. GM throttle body upgrades require a tune for proper idle, drivability and throttle response.

More Throttle Body Questions

Why upgrade a throttle body?
A performance throttle body can support increased airflow when the rest of the engine combination can use it.

Will this work on a modified vehicle?
Compatibility depends on the complete vehicle combination. Confirm the listed application and supporting components before installation.

Why Choose Granatelli Motor Sports?

Granatelli Motor Sports develops performance components for real-world street, street/strip, race, and custom applications, with an emphasis on practical performance, dependable construction, and integration into serious automotive builds.

Made in the USA in Oxnard, California. Orders placed before 3:30 PM Pacific ship the same day, and shipping is free on orders over $100. 90-day warranty, with extended coverage available. Shop all GM throttle bodies.