Speedometer question: 1960 Valiant

Gadabout said

Will do, or perhaps compare it to a GPS speedometer on my phone?

Click to expand...

That will work but....

Gadabout said

Got the speedometer in, and it works- sort of! Seems to register about 20MPH faster than actual, but that'll do!

Click to expand...

If all you did was change the speedo head, and you are 20 mph off, then either the new head is out of adjustment OR the old head was out of adjustment and someone replaced the gear to compensate.

So by checking miles you will know which it is.

Miles correct.... speedo head is needing calibration.

Miles incorrect gear is wrong.