Is it easy to do?
How do you do it, if not what is a decent price to have it done...

Thanks in advance.

basically you need to have a ratio box made up to suit your vehicle...

its an adaptor that fits between you gearbox and the cable at connection point..

it contains 4 gears that adjust the ratio of turns accordingly to correct your speedo..

cost me $120 to get made but i got quoted up to $260.. so shop around...

good thing about it is if you ever change diff ratio's/wheels size and want to correct it again it will only cost you about $30 to replace the smaller gears for what you need.

good luck

Interesting... So theres no other way?

Basically, My 120y has an original 120y speedo, a standard 4 speed gearbox, and also a standard diff (however the diff is from an auto, not sure if the ratio is different)

Even though they are all original parts, the speedo is not right...

yeah it may be a different ratio... the best way to fix the speedo would be to replace the speedo drive in the gearbox... unfortunately these gears are not available in different ratio's... which is why you need to get the ratio box made up to correct it.