I have a 79 Malibu with a mild 350 in it. For some reason when I take a timing light to it and try to set the timing, it wont idle. I tried setting it at 36 degrees total and when it goes back to idle it just dies. Vacuum hooked up or unhooked it does the same thing. Ive tried tuning the carb differently, changing the air mixture screws and idle air bleeds, i even rebuilt the carb. All the plugs and on tight and ive checked to make sure all the timing marks line up with tdc. But I still cant get it to idle until 25 degrees initial timing. Please help!