Engine rebuild pros and cons of zeroing out the speedo
 

I'm having my engine rebuilt and would like to add a zeroed out speedometer. I have an extra speedo and am thinking of sending it to NHS for fixing and zeroing it out. Will keep the original at the set mileage and if ever it can be sold with the car. So good idea or not. What's the pros and cons of switching it out?

the odometer? I would keep it the same and not roll anything back. Keep records however you have to to keep the data clear.

Zeroing it out will open up all sorts questions in people's heads at purchase time.

If it is accurate to car currently, I would leave it alone. If it is already wrong, then doesn't matter much.

in NJ that would mark future titles. I wouldn't do it.

Didn't think of that. Yes it would put a red flag on the title.

Why would you replace the original speedo with a "fixed" non-working one instead of just using the original? The car's odometer is the mileage for the whole car, not just the engine. Chassis miles matters. Doing something like this would make future prospective buyers run for the hills.