Speedo drive components missing

[harrymini]

Got a Dam5626 gearbox with 3.2 diff that is missing the components to connect the speedo cable to.
I know i need the part number 2a3624 number (2) on the diagram, but unsure of the speedo drive i need, im unsure of how many toothed drive i will need for part number (1)?

The speedo im using as a 1376 TPM

Screenshot 2020-09-29 at 17.55.06.png

Thanks in advance as im sure most of you will know what i need

[Spider]

Sadly, it's not quite as simple as that.

As well as the FD Ratio, you need the Rolling Diameters of the wheels and the Speedo TPM.

[Louis]

Guessworks site has the calculator tool for the ratios if that helps?

http://www.guess-works.com/Tech/ratio.htm

[harrymini]

Thanks guys, rang guessworks today and they have sorted me the correct parts to sort the issue.

Thanks John