Mellow, the Unilite should be fine, especially since it is free. If you are running a Chevy you need the ballast resistor. Did you get the mating harness also? If not you'll need to rig something up or buy one. Suggest you upgrade your coil also. If your running a stock or mildly warmed over motor running it without a spark box will be ok. Adding a spark box does make a difference though, just depends on your application. Most don't like the unit 'cause it steps down the voltage to the coil (ballast resistor). Putting a spark box on allows a full 12V to the coil and Mallory supplies a "plug" that allows you to bypass the spark box and limp back if box goes bad. Take Dimarco's advice and check out the web pages. Also, ALWAYS disconnect the dist from power when doing anything electrical, that includes charging the battery or even just removing a batt cable. Unlites are sensitive to electrical spikes and you'll blow the module in a heart beat.