Installation Instructions for 15407 Vortec Throttle Body Spacer with Helix Air Flow Technology 

for 1999-2002 CHEVY 4.8L & 5.3L & 6.0L 

Installation Instructions: 

1. With engine off, remove air cleaner assembly from top of throttle body unit. 

2. Using a 10mm socket, remove mounting bolts from the front side of throttle body. Remove throttle cables and wire connectors. Now remove throttle body. Leave original gasket on intake if mileage is under 70,000. 

3. Remove the three throttle body studs from intake. 

4. Remove the three bolts on top of intake that hold the throttle bracket. Set two aside to reuse (see illustrations below) 

5. Install linkage plates using two 6mm screws. Install throttle linkage bracket to the plates with the two screws that were set aside from step 4 above. 

6. Install vortec spacer on intake. Install gasket. Install throttle body unit. Bolt down with three 6mm x 60mm bolts and washers. Torque to 6ft-lbs. 

7. Install throttle linkage and wire connectors. 

8. Inspect throttle for open and closed travel. Reinstall air cleaner housing. 

9. Start engine and let idle for approximately five minutes. Drive the vehicle for approximately fifteen minutes to allow the computer to relearn.

STATE OF CALIFORNIA 

AIR RESOURCES BOARD 

EXECUTIVE ORDER D-623 

EXEMPTIONS