Yeah, 100% legal to convert. However, a RHD vehicle imported to the U.S. must go to State Patrol and be made sure that it has all the 5mph bumpers, and the swap is legit, and all the parts match the VIN, and the OBD is functioning, and all signals and gauges and everything works, plus it has to be tracked through customs and all the previous owners, a receipt for the car must be provided from the guy in JDM land that sold it to you, and blah, and blah blah blah. A whole bunch of stupid shit. Plus, it costs buckoo bucks to do all this too because the state has to overpay it's lazyass employees to look at your car. Another risk you run is that if they think anything is fishy about anything, they can confiscate the whole car for up to thirty days, no questions asked. It suxors my boxers.