Underscoring Rick's comment, my only problem has been with a faulty high-pressure fuel pump on my Roush EFI, which Roush replaced under warranty. Apart from that my SPF has been trouble free. I would qualify this, however, by adding that I had my SPF roller delivered from the factory directly to Dennis Olthoff. I then bought what I felt were the best components in the Roush 8 Stack EFI smallblock and RBT transaxle, and had them shipped to Dennis to install for me. Dennis incorporated numerous upgrades like an improved cable shifter, better radiator fans, and lots of little things that he knows are needed to make these cars the best they can be. I've done a few little things myself, like installing Dennis' interior door latches, and I will be replacing the windshield wiper transmission this winter. (The wiper thing only applies to the very first batch of cars) I can't recommend Dennis highly enough. Other owners in my area who had local shops do their install have not had such a happy experience. Not because of the SPF product, but because of drivetrain parts or their installation.