Do I need a CDI box to control timing?
No you do not. Our ECU can drive your coil directly, BUT it can also fire a CDI box if you have one or wish to use one.
But.........
If I have an HEI, can I use the timing control feature?
No you cannot. You will be running what we call "Fuel only". You still have an awesome system and we love this setup due to the high reliability of the HEI so don't be afraid to keep yours if you have one. They are great units!
