Where can I get a metric (KMH) speedometer (faceplate only) for my 96 Chev Express Van

There's a place called Specmo- if you search for it, you'll find it on the internet. If it's possible to swap that part, they can supply it. I seriously doubt it's that easy and you would need to change the whole cluster, which they can also supply and program to your mileage so nothing else changes. I have no affiliation with them, but have purchased 4 or 5 clusters from them over the years. It's where the ones from the GM dealer come from on the older vehicles.