I dont know what kind of electronic ign. changeover you are using but some are designed for use without the resistance in the circuit. You may have weak ignition. If you dont have the destruction sheet with it you may contact the company that made it. 61 models did not come with EGR. If its on there its manifold is 73 up. It would not lickly be causing this problem. It usually causes ruff idle. If it has a vacuum hose hooked to it try running it without it hooked up.
