I doubt you would get them to fit as the spacing is bound to be further apart given that the head is not cramming both onto the same side.If you measure them up I'd bee keen to
know the outcome.

What about putting E15 rods in too? is this possible? if not can you get rods which will allow me to do this? are there any other pistons which will lower compression for a
turbo in an A12?

I'm planning to reco my engine anyway so I may as well spend some money on the internals... Should I get the block O ringed?

The stroke of the A12 is 70mm. All the larger engines are longer. A14 is 77, A15 is 82, E15 is 82.
The lower compression height/pin height means the distance from the centre of the gudgeon pin tot he top of the piston so a lower comp height should also give lower compression. Additional
porting of the combustion chamber will also help.
The comp height of the A15 was 30.00 as opposed 32.40 on the A12. There is also a piston for the 76-78 Honda Accord that has a 74mm bore and comes in a 74.75 oversize. It has a 27.1 comp
height and a 17 mm pin dia.
O ringing is fine but if the motor is set up properly it shouldn't really need them. It is really an answer to another problem. Eg compression to high, to much boost, to much ignition,
fuel octane to low. All of which leads to detonation (erratic combustion). I believe a motor set up properly should not need it. If you were running that much boost that you needed them
then I suggest the rest of the motor would not last long unless you are using forged pistons and custom rods. Hardly worth the expense in a pushrod 1200 I would suggest.