Does this only occur at road speeds, in town driving or idling? Do you have the hood to radiator seal installed? Where's your timing sitting at initial and full mechanical advance? Is the car running lean? How do plugs look? What gauge are you measuring by? Not being a butt, there's a whole lot of things that play into these types of issues, just trying to pull a little more info.
This occurs at both highway and idiling, i do not have a hood to radiator seal. I do not know the timing but car runs great and plugs are clean. Measuring by mechanical gauge inside car and laser thermometer. Thanks for the feedback
