S15 spedometer question

[Tenchuu]

I thought I'd throw this one out there. Can you have a S15 setup and keep the US speedometer. If not do I just need an aftermarket one? I know the speed sensor is in the rear diff so I konichiwa ed the engine, tranny, driveshaft and diff from the S-15 over here. Got to love friends married to japanese locals.
I won't swap for about 5 more months. any info helps.