Having a pretty severe issue with my car lurching when I'm just trying to cruise. If I'm under throttle it is much better but it's bad if you're just maintaining at a steady throttle. It's a 351-C that has an Edelbrock 630 carb, 4-speed, stock manifold, Pertronix ignition, new wires, new cap, new plugs, good gas. It's got a slightly lopy cam, not sure specs because it's the way I bought it. Any ideas would be helpful.