Speedos.
 

This thread is NOT about swimming trunks!!

I was in the scrappy today getting engines. One came from an Escort and I really liked the look of the speedo in it as opposed to the sierra one. So I've brought it away with me.

Now I've pulled the escort and sierra one apart today and both speedos have 1000 rev/Mile on them.

My thoughts are that if they are reading the same mileage then they must register the same speeds. Is it that simple?

Yup, that's about it. When I built my Robin Hood it started with the Sierra speedo, I then went over to a set of instruments out of an Escort Mark1 1300E, the speedo was 1000/mile on that too and it read perfectly.

I believe most, if not all mechanical speedos are 1000 rev/mile, 625 rev/km on metric ones. So it makes a lot of sense to pick up the best looking instrument cluster from the scrappy. Escort should work like a charm, as the fuel float and temp sender parameters will likely be the same too.