What motor would fit in a 3.0 ford ranger 2000??

No, nothing about the vin number has to match and engine you want to drop in it. Just put an engine in the size you want. If you want some giddy up drop a 351 in there. If not just throw in some 6, or even a 4 if you could care less. I assume you would not be doing this yourself, so it doesn't really matter if its a little tricky does it?

Check with a honest engine rebuilding shop and ask them because I know that some Ford Explorer engines will not interchange at all, they all look the same but they will not work, also the VIN is some cases has a lot to do with this.

What is wrong with your engine? Those 3.0L Vulcan V6s are relatively trouble free. With that said, it is understandable that you will have a hard time locating a donor 3.0L engine only compounded by the fact that you have a Flex Fuel 3.0L, as the 'V' engine code denotes. That engine is also used extensively in the Taurus as you probably already know. However, you would need to find an engine that came from a Taurus with an eighth digit VIN code '2'. The two use different engine oil pans, oil pickup, as well as intakes. This means the transferring of a lot of parts will be required if you choose to use a Taurus 3.0L. The best case scenario would of course be, if you could locate another Ranger 3.0L. Hope this helps.