Depends what your end game is. If your looking to sc or turbo it the USDM one is probably better since it has a 10:1 compression ratio. If your looking to go all motor you'd be better off to start with the JDM b18c since it has a 10:6 compression ratio. Not saying you can turbo or sc a JDM motor, but you'd prob want to get the compression down on a JDM motor before doing so. More chance of kaaaaaaaaaaaabooooom!