I've installed 2 On 3 kits on my cars. Just sold my 90 after a year with the base On3 kit and no problems. My other car is apart right now but I've had the On3 Kit w the upgraded MP70 turbo on it for over a year. W the 331, TFS190 heads, Fcam, Victor EFI intake, 42lb injectors it made 497 rwhp at 4psi. And promptly split the block in half! I am getting ready to install an On3 kit on my new 87 notch project. Great bang for the buck and no problems in over a year.