Speedmaster 1-148-001 Chevy BBC 454 Downdraft 8-Stack EFI Intake Manifold System Polished

The Speedmaster 1-148-001 is a complete downdraft 8-stack electronic fuel injection intake manifold system designed for Chevy Big Block 454 engines. This stunning polished aluminum system combines the aggressive appearance of classic individual throttle body stacks with the precision performance, drivability, and fuel efficiency of modern EFI technology.

System Features:

• Eight precision-cast aluminum 50mm IDA-style throttle bodies with CNC-machined, heat-treated 6061 aluminum construction
• Individual throttle body design delivers superior idle characteristics and instantaneous throttle response
• High-flow capacity capable of supporting high-horsepower builds while maintaining excellent emissions and fuel economy through precise air/fuel ratio control
• Integrated progressive linkage system with throttle stops, idle controls, lever arms, and balancer all in one assembly
• Single screw adjustment for easy front-to-rear throttle shaft calibration
• Fully indexable eccentric cable pulley on bell crank ensures smooth low-speed drivability and proper full-throttle geometry
• Precision-machined butterflies measured and fitted to each individual bore for tighter tolerances and improved sealing
• Butterflies secured to centerless ground brass shafts with split screws for reliable, serviceable operation
• O-ring seals on lower mounting faces prevent vacuum leaks
• Complete polished finish for premium underhood appearance

Required Fuel Injectors (Not Included):

• Style: EV6 (USCAR/Jetronic)
• O-ring Distance: 1.480 inches
• Connector: USCAR plug style

This complete system provides everything needed for an 8-stack EFI conversion, combining race-inspired looks with modern EFI performance and driveability. Compatible with aftermarket EFI engine management systems.