The last several cars I’ve done for customers, I’ve used the complete FBO system. They seem to start better and run better than the factory ECU. They are of questionable quality. I’ve not used one in years. I’ve got and MSD on my Cuda. It’s went out once but I had an older unit for backup. Some of the new MSD unit are giving trouble. My biggest concern with MSD is breaking down on the road. I think these old cars need a backup ignition in the trunk that you can make a repair on the spot. Who wants to be stranded anymore. The Petronix unit is not easy to change in a pinch. The good about the FBO unit is a stock ECU and a ballast resistor change will get you home if the FBO unit goes out. I have not had one fail yet though.