There were a number of different versions of both the four speed & five speed 56A gearboxes.
My Datsun 1200 competition books shows a standard four speed, as well as an option 1 & an option 2. ratio set.

The five speed is shown with standard ratios as well as a 'close ratio' option.

The B210 competition parts list shows only the five speed, which is now described as an 'option 1'

All of these gearboxes have direct drive in top gear.

The 60 series five speed gearbox is mostly found with a standard five speed shift pattern & this is an overdrive box. There is supposed to be a dogleg, direct-in-fifth version, but I don't recall anyone saying that they have ever actually seen one.

I don't have any of the competition manuals for the B310 either, so I cannot advise what go-fast options were available. Sorry.