California vehicle code: "28051. It is unlawful for any person to disconnect, turn back, or reset the odometer of any motor vehicle with the intent to alter the number of miles indicated on the odometer gauge."
So, it's illegal. However as a practical matter the DMV provides a number of mechanisms for declaring the set back has occurred due to repair, etc., so as a practical matter you can probably get away with it as long as you don't hide it. Or put a piece of black tape over it and it won't bother you.
I would NEVER do a roll-back to hide something. I was basically referring to registering as a new build and the chassis, engine, etc. would in essence be "new". Thanks for your input though. :thumbsup:
Mr. Wolfe