hi everyone, I have been working on a 1968 Newport....bought it last July. In adjusting timing and idol, I can’t seem to get the curb idle at the spec from my FSM. It calls for it to be set at 600- 650rpm.... but as soon as I get it below 725, the carb starts to have a high whistle sound. Any ideas as to what causes it to do so? Next question..... I upgraded to a Pertronix mechanical distributor, it seems as though the base timing is way advanced from the FSM spec, is this normal.... the manual spec says base is At 7.5 and it seems to run pretty well between 24 and 28. Thanks for your input! ps.... I have a new timing light, digital, with advance and rpm.... among a coiuple of its options.