I have a 03 California model (235 hp). I am not happy with the performance of this truck. My old 460 pulled better than this does. I tow a trailer that weighs around 10k, truck just won't power up the hills. I lock out overdrive but still can't keep the rpms up. Had the ECM changed out a few weeks back, seems to be running worse since then. Originally had the flash done that seemed to work wonders but do I need to have it done again since the ecm was replaced? They said they loaded the latest program, would this have the flash incorporated?? I'm planning on installing gages soon, and also planning on some kind of box not long after. Even my wife notices the difference. Thanks. John