it isnt quiet clear about how much higher the JDM pistons are. but f23a1 are about 9.3:1 and i herd jdm pistons being anywhere from 9.6-9.8:1
pretty useless and expensive way of raising your compression. if you need USDM f23a1 rods and pistons i got a set ( just incase you burnt up a set and want to replace them ?)
If you need that minor of a compression ratio boost. id just deck the head a bit. but then you will need a tune to clean up the fuel/timing tables to see benifts from it