The JDM hiper has piping that is 20mm larger than the US version so it is louder and deeper. The JDM Hiper made 6 more rwhp than the Super Dragger. I would guess that the US spec would probably give at least 15 less hp than the JDM version.
I've got one for sale that is in Irvine if you're interested. You can come pick it up for $500.