Ok

not 100% sure, only difference i can think is between the early ('73 and before) and later blocks you cant because of distributer location : early - at number one spark plug. late - between 2 and 3 plugs. still not sure if there is a difference in the actuall dizzy ??? but what you really should look into (especially with all your other new bits going in ) is one of these little puppies at the bottom of the page definitley a faultless upgrade

Well, I haven't actually tried it, but I can't see why it wouldn't work. Just modify the bolt-down bracket similar to the new-to-old swap.

I've got some comparison pictures of the 2...but if you have both I think the A14 dizzy is better - better able to handle high rpm

Dizzy thread

it seems possible, but why?

you can use them, just swap the base plates... also make sure you dont accidently get an electric dizzy, you must sell it cheap to me :)

If you plan to use the distributor from a 1970 to '73 Datsun 1200 engine, then you will need to switch the stamped steel mounting plate from a 1974 or later distributor. If the new distributor is from a 1974 [120Y] or later A12, then I believe that it will drop straight in.
The advance curve will be diferent, but the engine will probably run just fine anyway.

it runs fine, once you install it, with the new base plate....it does drop straight in, conversely you can do the same to run a later model dizzy in a pre 73 a12.... and they tend to run better (from my experience)