I have been driving my 440 Dart Sport for 10 miles at a stretch or so. Engine is used but no smoke or low op with new gaskets and a .450-.455 cam, SD intake, and an Eddy 600 (just a carb to get the car going carb-runs perfect on my other rigs).

The car has a bit of a rough running condition out on the road at cruise. Kind of a light bucking or backfire here or there at speed. If you rev it at idle it doesn't clear out quite as smoothly either as it should. Just kind of hick ups and pops mildly here and there but will pull RPM.

Timing is this: It has about 36 degrees at 2300 RPM with the vacuum advance plugged. I set this with a dial back light. I had to go over 20 degrees initial to get that though. It starts ok and pulls 17 +/- inches at 800 RPM idle. Runs good down low.

The wires and new, plugs are new, I switched cap and rotor etc. with another set off of the shelf.

The car acts the same at cruise no matter where the timing is set at within reason. The car is driveable as is, but it drives me nuts with the mild issue.....

Is there a chance that the control box, coil etc. could be part of this?

The ballast resister is stock 1974. The control box is stock. The car sat for 20 years so who knows what is what there.

The coil is an Accel Yellow coil that is round, I believe it was from a points application, not sure that it matters.

Thoughts or ideas? I should say that I drove it very briefly last summer and it was the same.

Carb? Ignition?

Thank you, ROB