:rocker:What is the firing order on the 65 401 nailhead, and what is the timing supposed to be. I have some acceleration knocking and will check the timing, but also will add some lead to the gas, middle grade, that I have been using.The car has 39,000 original miles and is a daily driver to shows and around the neighborhood.. But does knock under acceleration after it warms up a bit. I must mention I live in Arizona and the warm summer temps probably don't help. Bill