LT230, what Speedo drive gear do I need??

Hi all,
I've searched as best I can and struggling to find what I'm looking for.
Just picked up a 1.6 box to replace my 1.2 as running 36" tyres now so she's was a bit gutless.
Anyone tell me what speedo gear I need to fit to get my speedo reading correctly? It's currently 10mph slower than it should be any idea what gear will be in the new 1.6 box? Will it be any better than the 1.2 gear?
Cheers

the one out of your old t/box , ratio of box doesnt effect speedo drive ,tyre size and diff ratio do though, for large tyres a blue one is the best fit you can get frc3310

Thanks James I'll get one on orders
Cheers