Over the years Ford used both ported and manifold vacuum so it depends on the distributor and diaphram he has.
If you have a good centrifugal advance distributor I would say to use it as the advance curve can be tailored to your intended use, and if you have it checked on a machine you can have the curve set where you like it. The centrifugal advance distributors are great with a Petronix magnetic pick up system. No points or condensor to fail, or pit or have the rubbing block(s) wear out.