I have one on my corvette (75) zz383. Well after we ironed out all the kinks it runs good. Blew an o2 sensor just tuning it. Ended up putting innovation motorsports adaptor on it to move it a little. Pin assignment was wrong from the factory (first 75 units shipped or so - just my luck). I have the computer controlled hei hooked up. Make sure that's synced the right way (check holley forums) or you'll chase the timing all over the place. Other than that which was just my luck items it is a simple system to install. I however did not bother with the handheld and set it up with the laptop almost from the get go. More tuning options if your going to dyno tune it.