Getting hung up on a dwell reading is wasted effort. Set the point gap to the specification the distributor serial number calls for (not the year of the vehicle or the engine), set the spark timing, and drive on. There's no telling how often a stovebolt distributor has been changed over 70 years or so, and not all distributors have the same dwell specification.
Jerry
There’s a wrinkle I never knew about. Where would a guy find points gap by distributor serial info?
I actually did set my gap via dwell last time I did it. I thought it worked pretty slick but I may have just gotten lucky.
