This Trigger Wheel Package is designed for all
Big Block Chevrolet engines utilizing an 8" harmonic damper.

Congratulations on your purchase of the Big Block Chevrolet Trigger Wheel Package! This trigger wheel provides a high-resolution trigger input to the Electromotive computer on your Big Block Chevy-powered vehicle. This kit requires no machining or welding, and is a simple bolt-on.

Parts List:

1. 2. 3. 4.

8-1/4" Trigger Wheel 1/4-20x3/4" Socket Head Cap Screw 10-32x3/16" Set Screw Magnetic Sensor Bracket

Q'ty 1 Q'ty 1 Q'ty 1 Q'ty 1

P/N 220-72825     P/N 210-72801

Directions:
1. Remove the pulley from the crankshaft damper.
2. Turn the engine to Top Dead Center (TDC) for the #1 cylinder. The more accurate you are with obtaining TDC, the more accurate your timing settings will be.
3. Remove one of the right side bolts of the timing chain cover, and install the magnetic sensor bracket (#4) in its place using the ¼-20 cap screw (#2). See the attached picture for bolt removal. Make sure that the sensor hole in the bracket is aimed toward the centerline of the crankshaft.
4. Place the magnetic sensor in the bracket, but do not tighten the setscrew.
5. Hold the trigger wheel on the damper such that the trailing edge of the 11th tooth (after the two-tooth gap) is aligned with the center of the magnetic sensor.
6. Install the original pulley set over the trigger wheel using the bolts to secure the pulleys and trigger wheel to the damper. Make sure that the engine is still at TDC, and the trigger wheel is still aligned correctly with the sensor.
7. Adjust the air gap between the trigger wheel and the magnetic sensor to be 0.050". This is best done with a feeler gauge.
8. Tighten the setscrew (#3) on the magnetic sensor bracket. It is advisable to use a low-strength threadlocker on the setscrew.

Following successful installation of the Big Block Trigger Wheel Package, you will have an ultra-high resolution crank sensor signal going into the Electromotive computer on your vehicle. Should you need any technical support in your installation, please feel free to contact us.