Thanks for the info. GF.
Had a bear of a time finding parts, which I finally gave up on, for the original distributor (circa 1982) which was electronic with an external ECU, so I figured the hell with it and bought a new Mallory distributor with the ECU built right in. Double element ballast is replaced with a single element and a fair amount of engine harness wiring goes away. Problem rebuilding distributors is calibrating the advance curve. If the curve's off, performance & efficiency go out the window. With this new system everything's now current production.