have been running them since 04, first on my 03rx and now on my 05 rx. i removed the tunnel protectors and am running the ice ripper 1 1/4 with no problems. as kinger said the speedo is right on, but the odometer reads a little low. i also have a 136 expert x with 8 inch rear wheels to match the drivers. the larger drivers also improve the track approach angle slightly. i run 22-42 gears with overdrive clutches.