I have a '65 fastback with 289, Holley. Just installed the JME gauge cluster with tach. Took it for a spin and it runs great, tach seems to be working fine. Runs like a rocket to 5,500 rpm, then starts to lose power,not as abrupt as rev limiter, but that is sort of what it feels like. I do havea Petronix igniter. Do these things have built in rev limiters? I just bought the car and am unfamiliar. Thanks for any help! John