Lagwagon, the difference between the
A14 & A15 is the crank,the A15 has a 5 mm longer stroke. The con rods are the same, so the difference in height is in the gudgeon pin position in the piston. Using the A15 crank with A14 rods & 76 mm(stock bore) A15 pistons will give you a capacity of 1488 cc's, identical to the A15. You can then get 76.5 mm pistons or 77 mm pistons as a stock replacement to allow you to clean up the bore. Being such a small overbore you shouldn't have too much troubles with the compression.78 or 79 mm pistons are available,usually they are for a Mazda engine, & i think you have to bore out the gudgeon pin holes to suit the Nissan Gudgeon. My suggestion would be to get some 76.5 mm pistons from a Nissan dealer & get the block bored to suit. You then have 2 more overbore sizes left in the block, so you dont have to throw it away when it wears out.