[rotorwrench]

Chevy and Mopar distributors can be modified to work well with multiple carbs on an 8BA family flathead V8. As mentioned, the centrifugal advance can be curved for a flathead easily enough. The vacuum retard can run off manifold air pressure if the unit is equipped with an adjustable vacuum can. It takes some tweeking to get the vacuum retard to work well under load but it can be done. This gives good performance as well as decent mileage. Flatheads can be relatively fuel efficient if a proper set up of the ignition system is done.

If running a stock carb, the old load-o-matic can be made to work just fine. The carburetor vacuum signal is from the venturi so it doesn't respond well to manifold vacuum.