Thanks all for your help.

Adam: Do you think if there are less gears then there may be less drag hence a smidgeon more power?

At this point I should admit my engines will never be on the road again. They are for my son's Ministock. Sorry to all those purist's out there.

Quote:

As WE know it the front mount distributor is the 1200 engine and the mid mount distributor is the 120Y engine.
They also need different engine mounts for each as the mount position changes. If for example you are to use the 120Y engine in a 1200 you will need to fabricate new mounts.
There is a difference in the camshaft in the number of gears so a 1200 cam cannot be used in the 120Y engine etc. We had a cam grinder grind a cam that he had sitting in his old cams shelf which he said would fit our engine (we did not see it beforehand) and it was the wrong one of course.
The parts lists show all parts such as bearings and rings etc as common between the two engines.
The larger engines such as 14 and 15 have similar configurations to the 120Y engine
Adam

the earlier A12s (from 1200s up to 73 i think) had the dizzy at the front of the engine and the alternator on the passenger side.
later A12s (which are more common) from 120ys and sunnys had the dizzy back further, and the alternator mounted on the drivers side, this made room for a aircon pump where the old engines has there alternator

as for performance, i dont think it really changed in that aspect, but some one with more experience will be able to answer that

these are the origonal dadsun 1200 (b110)
motors the motors with the distributors mounted to the back are from the 120y and datsun sunny

I'm new to Datsuns so please forgive my ignorance.
I recently saw an a12 engine with the distributor mounted up the front below number 1 plug. I own 3 engines, all with it back under number 3. Can anyone give me some history on this and is there any performance advantage with this engine over the more common ones I have?