I have the Fitech power adder on a 410 small block based on a 360 with a procharger. Technical support is everything on a system like this. Fitech technical support leaves a little to be desired. I got the bugs worked out and the system works great now but it was a real struggle for a while. Few of the issues I had is that they are sensitive to fuel pressure, the drivers for the injectors in the computer can not handle excessive fuel pressure, and the system does set codes but Fitech gives you little help in figuring out why these codes set. The pressure regulator they use is for a VW 1.8 engine, at the rated 650HP it will not return enough fuel at idle and the driver can get hot and shut down. It is picky about what distributor you use if you want the computer to control ignition timing, buy a MSD billet, only one I could get to work right. Wrap all the wiring harness with a braided sleeve, they are very sensitive to RF noise. After I got those bugs figured out it starts and runs great on pump gas and even gets decent fuel mileage. The hand held controller works well. Also the hand held unit may not have all the features activated, the tech guys had to help me activate certain functions.