BBK 1539 Twin 58 mm Power Plus Throttle Body for 1989-1992 GM TPI 305/350

Vehicle Fitment

• 1989-1992 Chevrolet Camaro (305/5.0L & 350/5.7L TPI)
• 1989-1991 Chevrolet Corvette (350/5.7L TPI)
• 1989-1992 Pontiac Firebird/Trans Am (305/5.0L & 350/5.7L TPI)
• 1991 GMC Syclone (4.3L V6 TPI)
• 1992 GMC Typhoon (4.3L V6 TPI)

Fitment Notes

• Direct replacement TPI throttle body for GM 305/350 and select 4.3L TPI engines
• Designed for stock or aftermarket intake manifolds with TPI fuel injection
• Retains factory throttle linkage and sensor mounting locations

Features

• Twin 58 mm large bore design increases airflow over stock throttle body
• CNC-machined aluminum construction for precision fit and strength
• Precision die-stamped throttle linkage for smooth operation
• Double-sealed bearings with O-ringed throttle shafts for durability
• Improves throttle response, acceleration, and horsepower potential
• Direct bolt-on replacement - no major modifications required
• Includes gaskets and hardware needed for installation
• No engine tune required for basic installation in TPI configurations

Specifications

• Part Number: 1539
• Throttle Body Type: Twin 58 mm Power Plus Series
• Material: CNC-machined aluminum
• Bore Diameter: 58 mm per side
• Fitment Position: Between air intake and intake manifold
• Throttle Interface: Electronic or cable-driven as applicable
• Compatibility: GM TPI 305/350 and select 4.3L engines
• Included Hardware: Gaskets and mounting hardware

Included Components

• 1x BBK 1539 Twin 58 mm Throttle Body
• 1x Throttle body gasket
• Mounting hardware for installation

Product Description

The BBK 1539 Twin 58 mm Power Plus Throttle Body is a high-flow performance upgrade designed for 1989-1992 GM Tuned Port Injection (TPI) equipped vehicles. With its dual 58 mm bore design and CNC-machined aluminum construction, this throttle body significantly improves airflow into the intake system compared to the restrictive stock unit. Increasing throttle response and potential horsepower gains, it offers a noticeable improvement in engine performance and acceleration without requiring a complex tune.

Engineered as a direct replacement for stock TPI throttle bodies, the BBK 1539 retains all factory sensor and throttle linkage mounting locations, ensuring a straightforward bolt-on installation. Included gaskets and hardware make installation easier, and the design maintains smooth drivability while unlocking a freer-breathing intake path. Ideal for classic GM muscle cars like Camaro, Corvette, Firebird, and select GMC performance models, this throttle body delivers enhanced throttle response and performance for naturally aspirated TPI engines.